The fan switch is on auto, not on, and even tried a different thermostat and had the same results. Fan Coil generated Critical Malfunctions: o Code 44 – Motor Communication Fault Code 41 – Blower Motor Fault Furnace generated Critical Malfunctions: Code 15 – Blower Motor Lockout Code 41 – Blower Motor Fault (317) 555-1234 FAN: AUTO CALL TECHNICIAN OUTSIDE: 94 ALERT ! CRITICAL MALFUNCTION JOE'S HVAC SERVICE The mode LEDs will. If the fan still does not turn off, there’s a malfunction with thermostat or the furnace’s fan relay switch. The portion of the relay that opens and closes can be called the switch, contacts or points. Here's a pic of the resistors Which fan speed you choose determines which resistor gets "used" by the voltage coming from the relay. Search our portfolio of Potter & Brumfield Relays Models & Products and select your specifications. February 2, 2014 - If your fan no longer runs at the high speeds it used to, then it's probably worn out from years of use or has other issues that limit airflow. It wasn’t easy to replace while still on the vehicle but it can be done. On contactors and some relays this can be done by removing the device and merely looking it over. Your evaporator coil needs air to blow over it to complete your AC's cooling process. No moving parts mean that there is no bouncing or arcing of contacts every time the relay switches current to the load. When Fan is set to Auto, Fan goes to Moderate Speed. Probably the only way you’ll know whether or not you have a problem with the centrifugal switch is because the ignition control (circuit panel) is flashing you a code telling you that the switch is either stuck open or stuck close. Check Your Furnace Blower Fan. - The A/C clutch requested. Try unplugging the fan connector, relay or fuse. The HVAC fan speed pop-up box may be stuck displaying on the HLDF display screen only after adjusting the HVAC fan speed. COVID-19 ZETTLER Group Update. If your air conditioner is not working, the problem can often be pinpointed to the HVAC compressor. The fan will be ON if either of the switches are in the ON position, and the fan will be off only if both light switches are in the OFF position. I eventually removed the fuse (#25) to stop it and it worked, but now I obviously have no A/C or defog etc. 85 86 30 87 87a. -The core of the radiator is welded in vacuum brazing furnace, no epoxy. Use the schematics included in your owner’s manual to locate a path to the relay. Locate the fan relay. The problem could be a stuck fan relay or a crossed wire between 24v and fan wire. Fan Selection: Depending on vehicle design, the fans may operate singly or in. Fan Inoperative When Air Conditioning Compressor Operates. 110 volt AC power point. Gray (GL) Gray Low Fan relay Blue (B) (12VDC-) Blue N/A White (W) White Furnace or Heat Element relay 6799-730 SERIES CEILING PLENUM THERMOSTAT CEILING PLENUM WIRE* UNIT OPERATION Yellow (Y) Black Compressor Green (GH) Green High Fan Gray (GL) Gray Low Fan Blue (B) (12VDC-) Blue N/A White (W) White Furnace or Heat Element relay. Trunk lamp. Correction: If the pop-up box is stuck on the display, rotate the HVAC fan speed control knob one click, up or down. Order Now! Relays ship same day. Chevy Cruze 1. These problems are not easy DIY repairs and should be left to an HVAC professional. Fuel pump (FP) relay. So about a month ago or so the fan relay stuck open on my upstairs GOODMAN Heat Pump and today now the downstairs unit did the same thing. I have a 2001 Solara, and the heater/AC fan ONLY works with the fan control switch in the high position. The low and medium-speed relay has gone bad, and I think it's all integrated into the whole thing on a Cruze. If the relay’s on, it will switch off when the applied voltage falls below 0. Left Fan Motor connector disconnected. The EMR relay is designed for AC or DC source depending on the application it is used for. Check the contactor relay switch. If the fan didn't come on, you'd still be warm inside. the other two relays also look fine. INTRODUCTION Solid State Relays (SSRs) and Solid State Contactors (SSCs) are ideally suited for. These Hayden automotive electric fan kits are designed to allow your electric fan to turn off and on at certain temperatures. 9 Tdi sport), but apparently even same year models can have no high-pressure sensor, in which case it may be your regulator/compressor and a bigger price tag to fix. This is the black (BLK) wire of the fan motor connector. Radiator Cap. 110 volt AC power point. the only means of turning the air handle fan off is from the circuit breaker. • Install a Remote Temperature Sensor in the wall where the Thermostat is located. If it too much for you call a pro. 1 Remove the cover and clean the condenser and moisture-collecting (evaporator) coils. It the fan stops thats the one that is bad. Just keep in mind that many modern cars use electronic relays. If the A/C clutch is not engaged, the PCM will actuate the fan relay when the. I have an older gas furnace fan that will not come on. drive fan: Hd lps: 50: HeadlampsAir bag module (aux. The relay contains a low-voltage coil and a high-voltage switch, sometimes called "contact points. Restore the power and see if it starts. If the fan operates then you have a faulty thermal switch (assuming coolant temp is over 95C degrees at time of this check). Cooling Fan Relays and Fuses. 3 Inch 42 Frame 48 Frame GE 11 Frame All Refrigeration General Purpose C-Frame All General Purpose. Contact us or order today!. F71 (20A)Cigarette lighter. When the fan is on too often, or won't come on at all, a new relay may be the solution. If it's a multiple stage unit it will increase fan speeds to compensate for the compressor kicking into higher speeds. When the A/C switch is on, both the A/C Condenser Fan and the Radiator Cooling Fan are activated by the ECU, through the A/C relay. If your condenser isn't running, check the power to make sure the unit is plugged in. If you begin to notice a change in your fan’s speed – it seems too fast or slow – there are 3 key areas to have your Portland air conditioning technician from Clean Air Act inspect on your AC system: Motor Issues. This happens when the switch simply fails to shut off the fan after the burners have stopped and the air exchanger is sufficiently cool. But the truth was that we've swapped a sea breeze for a place everyone has told me is the hottest part of France in summer — and there wasn't even a fan, let alone air conditioning, in the house. I was originally going to bypass fuse 16 with an external fuse holder, but this fuse block was so bad I decided to replace it. Backup Light Switches Heater/Blower Fan Switch 1988-98 Chevy & GMC Truck. So the power has to run from the fuse, thru contacts in the relay, thru the speed switch, to the resistor module. Looking for WHITE-RODGERS Magnetic Relay, Enclosed Fan Relay (Heavy-Duty), 24 Coil Volts, SPNO/SPNC, — HP (1N185)? Grainger's got your back. This article is a little different and is less common than the other problems. I checked for stuck sequencer and no/nc contacts on th time delay relay for the blower. 0L Fuel Pump, Trailer Tow; 1992 Ford F-150 Custom 8 Cyl 5. 1995 T600 ac blower kicks on, then like a relay kicks out. The cooling fan relay is the relay that controls the engine's cooling fans. The pop up. Probably the only way you’ll know whether or not you have a problem with the centrifugal switch is because the ignition control (circuit panel) is flashing you a code telling you that the switch is either stuck open or stuck close. Wiring diagram says relay R46 high speed fan relay, but thats not on the relay. When the RFA module grounds terminal 86 of the RAP relay, the RAP relay energizes and supplies power to the RDO/PH fuse and the SUNRF fuse (if equipped). An AC relay will remain contact closed due to mechanical inertia and a little mechanical hysteresis and, the fact that an alternating north and south pole both attract the relay armature. Stuck relay on furnace board. Besides the coil terminals, you then can check to see if the the other terminals are good as well. Left Fan Motor connector disconnected. That is definitely one possibility. 0131M00429S Goodman 1/4 H. If the control board is at fault, replace it. If there is continuity across terminals 2 and 4, and the wiring to the motor is okay, replace the motor. If your furnace goes off on high limit or if one of the rollout switches are open then the furnace fan will run all the time because the furnace control board is telling the furnace that the furnace has over-heated and the fan. Your fan limit switch is located directly under your furnace hood and controls when your furnace blower turns on and off. The relay you swapped out is in fact the cooling fan relay, which is a multi-use relay, Porsche number 141 951 253B (worth about 5. Replaces the. For high speed cooling fan operation, the PCM grounds the high speed and S/P relay control circuit at the same time the low speed control circuit is grounded. I'm replacing the motor in my dryer and the blower fan is stuck to the motor shaft. If the fan runs but blows cold air, set the thermostat 5 degrees or more above room temperature to activate the backup heating elements. Car wiring question. This article is a little different and is less common than the other problems. Fuse holder 16 is melted. Learn more about Toyota Camry Solara at the Edmunds. Clockwise (CW) motor 4×4 relay. A clicking noise that starts off slow and progresses as the unit warms up could be coming from an obstruction to the fan or a bent fan blade. Bring your damaged relay with you to the automotive or electronics shop to ensure you're getting the right part for your blower motor. Tapping on the relay won't necessarily free it up. If the fan didn't come on, you'd still be warm inside. This is usually the culprit with most fan problems on the 05-09s. Turn the air conditioning unit's breaker off at the main electrical panel. Putting dc on an ac coil should work fine but be prepared for the resistance to be low. An electrical symbol is a small image used to represent an electrical or electronic device or function. The "change over relay" and the "right fan relay" are provided with ignition 12V via fuse 3 from the fuse box in the passenger compartment. Note: The 1N4148 diode is connected in a odd fashion for a reason. AC/heater blower motor relay – rear. When the ac is blowing hot, turn the AC to max cold and check if the clutch is turning. Fuel pump (FP) relay. Run a wire to the furnace, and install the Thermostat next to the furnace. The A/C relay is the one in the number one position, on the extreme right, Porsche number 944 615 113 01. The blower motor is crucial to the proper functioning of your HVAC system. By wiring these outlets to the relays we created a plug-and-play device that works on both ends. We offer a wide array of products with applications across many industries. R goes from transformer to thermostat, W/G/Y and other circuits go from thermostat to relay, and C goes from relay back to transformer to complete the circuit. I disconnected entire thermostat and also replaced with a new thermost but the problem remains. Buy Switches & Relays. As a result, the contactor is not engaging automatically so in order to have cold air in my house I have. On the ones I dealt with I replaced them with a more modern relay. Using your fingers, pull up on the outboard "latch" first, then the inboard one to remove the cover. The radiator fan is not controlled the same, the ECU turns it on with inputs from the fan switch in the cooling system. With a voltmeter, check across the low-voltage coil. Check capacitor : X: X: Thermostat wiring: Check thermostat wiring at heat pump. The PCM will actuate the fan relay whenever the A/C clutch is engaged regardless of coolant temperature and vehicle speed. On a 1995 Chevy Pickup it is located behind the glove compartment. Wire zones 2 and 3 the same as zone 1. The fan will be ON if either of the switches are in the ON position, and the fan will be off only if both light switches are in the OFF position. The HVAC fan speed pop-up box may be stuck displaying on the HLDF display screen only after adjusting the HVAC fan speed. The most common problem on these relays is an open or shorted coil. HZ432 zone panel controlling air-conditioning zoned with dampers and heating zoned with a zone valve or circulator relay panel. But when it happens, it might continue for a day, or half a day and then back to normal. I also saved the capacitor which has three prongs with orange and yellow on one,blue on another and the last has a red. The FRBii accepts incoming single phase power of nominal AC voltages 120, 208, 240 and 277. Additionally, many vehicles have multi-speed fans requiring as many as three fan speed relays for low, medium and high. Blower fan keeps running: A failing sequencer may have a "stuck" contact and keeps a heater coil and the fan and running. Disconnect the fan switch and tape the leads, if that solves the problem the fan switch is stuck closed. Relays / Contactors are nothing more than a switch. My rheem air handler fan will not shut off even when I adjust the thermostat setting to 'off' for both fan and unit. When I shut off the car after running it, the AC and blower motor fan continues to run after shutdown. The two relays will be the compressor and AC fan relays. Faulty Thermostat: If both the fan and either the cooling or heating system are running unexpectedly, you may have a faulty thermostat. When the relay is activated the AC condenser fan is switched on so that it can keep the AC. Cheap Air-conditioning Installation, Buy Quality Automobiles & Motorcycles Directly from China Suppliers:Cooling Fan Control Relay Switch Module 701919506A 701 919 506 A for VW EuroVan Sharan Transporter Seat Alhambra Enjoy Free Shipping Worldwide! Limited Time Sale Easy Return. Operating the electronic viscous fan clutch to maintain a reasonable head pressure is critical. Our fan coils and other Carrier cooling products will help push your cooling systems efficiency to its highest level. Your radiator fan relay is a two stage (speed) relay. 5 uf MFD 370 or 440 VAC Oval Run Capacitor PW-7. Radio (MCM) Instrument cluster (MCM) Clock. If not then the relay is stuck closed. This component "tells" the air conditioning fan to shut off once the thermostat reaches a reading equal to the temperature setting. If you can rotate the blade freely, there is a good chance it's your run capacitor. RR HVAC: Rear Climate Control: AUX PWR: Auxiliary Power Outlet — Console: IGN 1: Ignition Relay: PCM 1: Powertrain Control Module: ETC/ECM: Electronic Throttle Control, Electronic Brake Controlle: IGN E: Instrument Panel Cluster, Air Conditioning Relay, Turn Signal/Hazard Switch, Starter Relay: RTD: Ride Control: TRL B/U: Backup Lamps Trailer. An electrical symbol is a small image used to represent an electrical or electronic device or function. An aquastat is a device used in hydronic heating systems for controlling water temperature. 1988-1993: The two-speed fan runs on low. I had an Odyssey and the relay was fine, ended up being a bad $15 electromagnet in the clutch. Hi Folks I have a Vito W639 and the drivers side electric cooling fan runs all the time, i have checked all the wiring and the relay and it all seems to be fine, i took out the SAM and checked for both internal damage and water ingress and this looks fine. The FRBii accepts incoming single phase power of nominal AC voltages 120, 208, 240 and 277. Locate the fan relay. Glove compartment lamp. - Given irsmun's issues, the Mitsuba will not change anything b/c the Mitsuba relay was used to. If you feel warm air, the problem’s in the outdoor coil/condenser unit. The relay contains a low-voltage coil and a high-voltage switch, sometimes called "contact points. Theres not much you can do other than killing the power to the furnace itself. Those are the two low-voltage terminals on the transformer. 5) Fuse for fan first and second stage on fuse panel, #1, 30 amp 6) Relay for fan second stage on fuse panel, location #5 7) Relay for radiator fan third stage under dash, to left of speedo 8) Fuse for fan third stage, strip type 50 amp right next the third stage relay 9) Water pump on engine 10) Thermostat on engine 11) Hoses and pipes throughout. Additionally, many vehicles have multi-speed fans requiring as many as three fan speed relays for low, medium and high. it would appear somthing is stuck on/relay any advice would be appreciated. 30 amp, 277v LRA150, 17 amp, 600v LRA100. Each relay will control a single fan, and a 30 amp fuse is recommended for each relay connection to the battery. Trane Blower Motor Time Delay Fan Relay RLY2807 RLY02807 This is a brand new Original Equipment Manufacturer (OEM) Trane American Standard fan relay includes PC board, part# RLY02807 (also part# RLY2807, X39000937010E). As you can see from the diagrams above and below, it's really a simple circuit that not only provides the proper connections to control the cooling fans, but unlike the switch-under-the-dash method - you won't ever have to worry. The fan blower should come on. These Hayden automotive electric fan kits are designed to allow your electric fan to turn off and on at certain temperatures. As a result, the contactor is not engaging automatically so in order to have cold air in my house I have. Switch Switch Orange Wire Temperature Yellow Wire to + 12 Volts Black Wire Red Wire Holder Fuse Relay Connect to chassis ground + - Battery WHI-05-28-03 Wiring: Beforemechanical or electrical installation DISCONNECT BATTERY. If the fan operates then you have a faulty thermal switch (assuming coolant temp is over 95C degrees at time of this check). On the 78's its in a plastic relay block and the ones I dealt with the block was so badly melted you could not get the main contacts out. The same type of “Thermal Runaway” problem is also likely to cause failure of the ordinary “cartridge type” in-line fuse holders—It’s why we have supplied the 18gauge Fusible Link in our Relay kit. In stock and ready to ship. Each fan motor's connector has two wires coming out of it. * 1 - Blank * 2 - 7. I disconnected entire thermostat and also replaced with a new thermost but the problem remains. Use a quality 5A fuse. In this case, you can connect the switch circuit to circuit delivering up to 250 Volts Alternating Current (AC) or 220 Volts Direct Current (DC). Most likely I'll have to break it up and install a new blower fan. This video will show you how to properly diagnose your blower by using the multime. Unplug the harness to the switch and "jumper" the two harness connectors with the key "on". If you have 2 wires, High and Low activation, coming from your ECM, this splice will need to be cut to separate the blue and green wires. Essex contactor relay. The fan's relay coil does not show 24 volts except for a surge at start attempt. If you disconnected the thermostat leads at the furnace and the furnace is not in an open limit circuit condition then you probably do have a stuck fan relay. Note: The 1N4148 diode is connected in a odd fashion for a reason. - The A/C clutch requested. So the power has to run from the fuse, thru contacts in the relay, thru the speed switch, to the resistor module. Gas Heat cycles on and off correctly and keeps temperature per the setting on the thermostat. If you can rotate the blade freely, there is a good chance it's your run capacitor. If it's running off-high-off, the fan needs to be replaced. The problem could be a stuck fan relay or a crossed wire between 24v and fan wire. Fan Relay Board 2 (FRBii) – Installation, Operation, and Maintenance. 1) coolant fan(s) come on when I start car 2) temp gauge stays on C (dead) 3) AC does not kick in (blows air with no AC) This happens at random as best I can tell. It constantly has a 12v feed. To prevent the boiler from firing too often, aquastats have a high limit temperature and a low limit. My radio/AC fan/door locks/windows etc, are all still dead. Besides the coil terminals, you then can check to see if the the other terminals are good as well. Am i correct in my assumption. Relays / Contactors are nothing more than a switch. F75 – F76 (20A) Trailer socket. If not then the relay is stuck closed. There are several different compressor designs, but all perform the same function: they move, or pump the refrigerant throughout the system, and they compress the low pressure vaporized refrigerant into a high pressure vapor. High speed bypasses the relay and gives full voltage as commanded by the ECU. Thermostat turns on Gas burners correctly. Each fan motor's connector has two wires coming out of it. Locate the fan relay. If there is continuity across terminals 2 and 4, and the wiring to the motor is okay, replace the motor. You can now buy select products directly on TE. An electrical symbol is a small image used to represent an electrical or electronic device or function. 85 86 30 87. Our Smart Search accepts the following: Year, Make, Model followed by the part type Example: 2010 Ford F-150 Air Filter; Part number Example: 9004. The heat and or air will work and cycle on and off as normal. Trunk lamp. The main usage of the Relay was seen in the history of transmitting and receiving the information, that was called as Morse code where the input signals used to be either 1 or 0, these change in signals were mechanically noted in terms of ON and OFF of a light bulb or a beep sound, it means those pulses of 1s and 0s are converted as mechanical ON and OFF using electromagnets. Cheap Remote Controls, Buy Quality Consumer Electronics Directly from China Suppliers:433MHz Universal Wireless Remote AC/DC 12V 24 1CH Relay & Transmitter Remote Garage/LED/Light/Fan/Home appliance Control switch Enjoy Free Shipping Worldwide! Limited Time Sale Easy Return. Cigarette lighter relay. If the relay’s on, it will switch off when the applied voltage falls below 0. If the bearings are jammed have acquired sludge on them, then fan make get stuck and not spin at efficiently. Just your blower will run 24/7. I installed the duct fan relay in a box near the fan. Air Conditioning Relay (545) Multi Purpose Relay (518) Light Relay (436) Radiator Fan Control Relay (370) Starter Relay (296) Horn Relay (294) Blower Relay (282). If the transformer internal fuse is still OK, check output voltages, pins 9 – 8 (3. In all of the affected vehicles, an incorrect high speed cooling fan relay was installed. Test the contactor with a multimeter to see if it works. How Does the Limit Switch Work in a Furnace?. If it is not, check if the power wire to the compressor clutch is getting power. Most likely I'll have to break it up and install a new blower fan. RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. I then turn the dial to #2 and no cold air, no AC light on the dial 3. Opened it up cleaned contacts all seems fine. We also offer other Mercedes ac/heater related products to complete your Mercedes Benz climate control repair such as a Mercedes ac vent, Mercedes compressor relay, Mercedes ac hose, Mercedes heater hoses, Mercedes ac pressure switch, Mercedes receiver drier and lots more. Electric fan relay power. Data wires come out of the box and can be safely connected to an Arduino. 1992 Ford F-150 Custom 6 Cyl 4. The manual may refer to a blower relay, an AC relay, or a cooling fan relay. I would change the thermalstat first because it is cheaper than messing with your wiring and computer. The N/C switch goes to the Low sped which is the Heat speed and is controlled by a time or temperature delay not the fan relay. F71 (20A)Cigarette lighter. Trailer tow relay, battery charge. The connectors that can be removed from the block fit the new relay and the ones that were stuck had to be cut and replaced with new crimp ends. stuck fan relay or a bad sequencer. relay fresh/ recirc switch 248 239 304 45 342 248 25a cab blower 15a air cond 25a slpr blower 239 ground switched power cab fan low cab blower control bunk blower control bunk blower 45 248 342 152 239 diode heater/air conditioner without pcc: model 379 family sk25756 a 01. Here's a pic of the resistors Which fan speed you choose determines which resistor gets "used" by the voltage coming from the relay. The contacts of a relay or contactor must make good direct contact when energized for the device to function properly. Ignition Cylinders with Keys Horn Relay 1973-79 F100 F150 F250 1978-79. 0L 2014, GM Original Equipment™ Engine Cooling Fan Motor Relay by ACDelco®. ) Flash-to-pass. Two of the wires are low voltage and go to the limit switch, and two wires are line voltage and go to the fan switch. Like many household appliances, each of these components does their job both independently, but also in unison with the connecting parts and when one section of the system goes. The EMR relay is designed for AC or DC source depending on the application it is used for. If not then the relay is stuck closed. Hi,I have an older Bryant 75000 BTU Natural Gas furnace built in 1986 with a HH84AA 011 board. R1 pulls the 'RELAY' pin to ground so if anything goes haywire the relay will remain in the safe, off position. Tom and Ray say she can either fix her fan the right way, or take the cheap and easy way out--using paperweights to keep her stuff from blowing away. I haven't had a fan in 6-weeks (A/C season here is pretty well year round, with only Jan/Feb off), but as I was leaving NAPA, guess who showed. I replaced the OEM Valeo switch with a NAPA/Echlin piece ($36) and, sure enough, one pair of switch contacts (uppermost) were toasted. Bottom Row, Left to Right Radiator Fan High Speed Relay, ABS Control Relay with 10Amp Fuse, Window and Sunroof Relay Blower Motor and Motor Control Unit Check The factory Service Training book on the Digital Climate Control system used in the 1986-88 5000T/Q, "Digital Climate Control for the 1986 Audi 5000" has some great design and theory of. Disconnect the motor from the main power supply. 8L Fuel Pump, Trailer Tow. I felt like an idiot. Check for Line voltage across BR contacts. Browse a selection of ground fault relays from Littelfuse now. The two relays will be the compressor and AC fan relays. If it says cooling fan relay, it’s talking about the relay that controls the radiator fans. Checking the operation of a fan relay on your vehicle is an easy procedure. Fan speed switch has off, which cuts power from the contacts from the fan relay to the resistor module. ZETTLER Group North America Company Relocation. Right Fan Motor connector disconnected. When the relay is activated the AC condenser fan is switched on so that it can keep the AC. You might at first imagine that a faulty relay will cause the furnace's heating elements and fans to fail to turn on. This video will show you how to properly diagnose your blower by using the multime. Your owner's manual (!) should have a fuse/relay legend for the fuse box (es). , that powers it. If it isn't working properly then you will have high head pressure on your A/C system which can over stress and ruin your compressor. Essentially, this means that the fan isn't receiving the commands you're relaying to the thermostat. There are several different compressor designs, but all perform the same function: they move, or pump the refrigerant throughout the system, and they compress the low pressure vaporized refrigerant into a high pressure vapor. Tailgate release relay-lower. Use a digital multimeter (DMM) to test the resistance between each pole of the relay and the corresponding NC and NO contacts for that pole. When the car reaches operating temp, both fans activate at low speed. There's a relay that's mounted on/in the fan shroud at the plug. On a 1995 Chevy Pickup it is located behind the glove compartment. If something in the. I have been told I might have to replace the board as the fan relay may be. Gas Heat cycles on and off correctly and keeps temperature per the setting on the thermostat. The first and simplest area to check is the fan unit on the inside air handler. You might at first imagine that a faulty relay will cause the furnace's heating elements and fans to fail to turn on. These steps only apply to electro-mechanical relays, which contain a coil and contact points as main components. In stock and ready to ship. If the switch has completely failed and is stuck in the open circuit, or OFF, position, the furnace won't run. That is definitely one possibility. ZETTLER Group North America Company Relocation. To determine if the contacts inside a sequencer are faulty, the technician should energize the relay so the contacts are made and use an ohmmeter set to the RX1 scale. Two for constant 12v power and one for a signal from the ECM to tell it what speed is required. When the fan switch moves to any speed it energizes the coil in the relay which closes the contacts in the relay. When the fan in a car stops working on any speed but hi, the blower resistor (in Lexusland, blower motor control) is often at fault. 0L Fuel Pump, Trailer Tow; 1992 Ford F-150 Custom 8 Cyl 5. UEB1-70 Miniature Circuit Breaker Complies With Salt Spray ASTM B117-500hr. The fan flange is fairly stripped from me turning hard against it (I'm aware that it's a reverse thread). The last two values specify that the relay will turn on when 2. The most common problem on these relays is an open or shorted coil. Repair your Air Conditioner Switch for less. Hot air is vented outdoors, reducing the temperature of the space without using the air conditioning system. It is important to note, that there are a variety of reasons that your furnace won’t turn off, many of which are outside of your control. Connect an incoming pole of each of two of the relays in parallel. Hard Start Kit for slightly stuck Air Conditioner Compressors; Hard Start Kit for stuck Air Conditioner Compressors; Heat Pump Outdoor Motors and capacitors. I then turn the dial to #2 and no cold air, no AC light on the dial 3. Trailer tow relay, battery charge. Try unplugging the fan connector, relay or fuse. Motors; HVAC/R Components; Service & Installation; JARD; Danfoss; HVAC Equipment; Refrigeration; Resources. This typically happens if the engine is too hot, so be sure to check the engine temperature. Since the valve is an integral part of the sealed refrigerant circuit, proper procedures for recovering and then later refilling the refrigerant must be followed, to prevent its loss into the atmosphere. The air conditioning head pressure is reported to the ECU by a transducer located in the discharge line and will cause the fan clutch to engage almost every time the truck idles for a few minutes in warm weather. A transformer, usually 24 volts, energizes the contactor which has a coil built into it. The most likely problem is an internal short with your blower relay. My heater fan blower motor is stuck on high speed only. I'm replacing the motor in my dryer and the blower fan is stuck to the motor shaft. And any electrical device with a plug on the end — be it a light, a fan, or a blender — can be plugged and unplugged, as easily as you would with a simple power strip. It the fan stops thats the one that is bad. And keep in mind, it really doesn't hurt the motor or cost more money, running all the time. Using the splices provided, connect the LOW speed wire from your ECM to the Green wire going to the relay, and your high speed wire from your ECM to the blue wire going to the relay. Open the hood and do a visual inspection. it would appear somthing is stuck on/relay any advice would be appreciated. Selecting a Solid State Relay or a Solid State Contactor for start/stop control of an AC motor By Alessandro Bosio, Motion Control Business Development Manager, and Paul Bachman, Fellow Engineer Crydom, Inc. Testing automotive relays before replacing them is a good idea and it’s not to difficult. Tools & Downloads. So the power has to run from the fuse, thru contacts in the relay, thru the speed switch, to the resistor module. See which one turns off the fan. 2 Lubricate the fan motor bearings with a couple of drops of lightweight household oil (such as 3-in-One) if the motor has oil ports (some dehumidifiers don’t need to be oiled). If the control board is at fault, replace it. I finished wiring the fan using a 24VAC relay and the GRN (fan relay) and C(Common) leads from my thermostat. In my STS both fuse boxes have a number/color coded sticker inside the box cover. From standard solutions to custom designs, we offer reliable, cost-effective products for mechanical, electrical, digital, analog, miniature, and harsh environment. If the fan didn't come on, you'd still be warm inside. Gray (GL) Gray Low Fan relay Blue (B) (12VDC-) Blue N/A White (W) White Furnace or Heat Element relay 6799-730 SERIES CEILING PLENUM THERMOSTAT CEILING PLENUM WIRE* UNIT OPERATION Yellow (Y) Black Compressor Green (GH) Green High Fan Gray (GL) Gray Low Fan Blue (B) (12VDC-) Blue N/A White (W) White Furnace or Heat Element relay. If it too much for you call a pro. - The A/C clutch requested. This will be a set of contacts that are normally open. Theres not much you can do other than killing the power to the furnace itself. The manual may refer to a blower relay, an AC relay, or a cooling fan relay. When Fan is switched from Auto to ON, Fan goes to High Speed. Place the Inductor®In-Line Duct Fan™ in the opening, making sure that the fan blade can turn freely. Testing Automotive Relays Explained Defective Relay. The fan switch is on auto, not on, and even tried a different thermostat and had the same results. That is definitely one possibility. Easy to use parts catalog. Hello, I have a 2000 CLK320 and my fan runs continually even when the car is off and the keys are in my hand. ) If the fan takes off and then keeps going on its own, you more than likely have a bad start capacitor. In 940 cars, remove the same low-pressure switch connector at the receiver-dryer and jumper it: current comes directly from terminal 10 of the MCC control. Our Smart Search accepts the following: Year, Make, Model followed by the part type Example: 2010 Ford F-150 Air Filter; Part number Example: 9004. Blower fan won't turn off, fan speed won't change, and I have to pull a fuse to turn it off. And lastly, fixing this problem, usually isn't an expensive repair. What would cause the blower motor to be stuck on high? It does not matter if I turn the fan speed knob to 0,1,2,3, or 4, it will not change speeds or shut off. This includes the COM terminal, the Normally Open Terminal, and if the relay is a double throw relay, the Normally Closed Terminal. Five years ago, I replaced that relay with this updated solid state model (RLY02807). I have located the relay switch that looks almost impossible to access. With engine running, A/C on, and fan relay removed, check for battery voltage at terminal 2 of fan relay connector (Fig. You can now buy select products directly on TE. First, did you check the ac relay? You can usually swap the horn relay with the ac relay to test if its bad. And it cuts back off. Learn more about Toyota Camry Solara at the Edmunds. I replaced the blower motor resistor, but that did not resolve the issue. If you disconnected the thermostat leads at the furnace and the furnace is not in an open limit circuit condition then you probably do have a stuck fan relay. 5 Amp Discharge Warning Light * 3 - 15 Amp Alternator With IC Regulator, Emission Control System (1984-85) * 4 - 15 Amp. Switch Switch Orange Wire Temperature Yellow Wire to + 12 Volts Black Wire Red Wire Holder Fuse Relay Connect to chassis ground + - Battery WHI-05-28-03 Wiring: Beforemechanical or electrical installation DISCONNECT BATTERY. Locate the furnace fan limit switch. It is important to note, that there are a variety of reasons that your furnace won’t turn off, many of which are outside of your control. There's a relay that's mounted on/in the fan shroud at the plug. A sealed relay must be checked by determining if the contacts open and close when the relay coil is energized or de-energized. Fan mode usually results to lower power consumption because the compressor is turned off. Air suspension relay. MAX AC has the same results. Try unplugging the fan connector, relay or fuse. In the Kansas City area? HVAC Parts Shop 7252 W Frontage Rd Suite B Merriam, KS 66203. 3 - K6326, Unloader Relay (Salmon or White-Green) or K6327, Fuel Injector Relay 4 - K11, Front Windshield Wiper Relay (Green-Brown) P/N. In most cases if you miss diagnose the electrical problem and buy a new relay and it doesn’t fix the car, you’re stuck with the part you didn’t need. For high speed cooling fan operation, the PCM grounds the high speed and S/P relay control circuit at the same time the low speed control circuit is grounded. Locating the correct relay can be tricky. With a voltmeter, check across the low-voltage coil. The fan blower should come on. The temp gauge is either dead cold or normal. HVAC C-Frame Square Motor 3. The control board has relays that regulate the voltage to each component in the furnace. - The vehicle speed is less than 38 MPH. One time I had that issue and it ended up being that I had the 'fan' setting set to 'on' rather than 'auto' so the fan was on all the time rather than just when the A/C was running, lol. Thanks for reply. Tailgate release relay-lower. MFC1 Relay connector disconnected. Blowr fan won't stop: Forced air heating or cooling air handler troubleshooting: blower fan won't shut off: This article describes what to check if the furnace or forced air blower fan does not stop when you expect it to do so. This is pretty common on the Honda vehicles. If the fan doesn’t start running, you may have a bad fan motor. Left Fan Motor connector disconnected. it would appear somthing is stuck on/relay any advice would be appreciated. That is definitely one possibility. Generally wiring is in a functional triangle. Blower fan keeps running: A failing sequencer may have a "stuck" contact and keeps a heater coil and the fan and running. If the sequencer is stuck, the fan and the heat kit would stay on. Problem: Poor airflow due to dirty air filters causes the furnace to overheat and damage the sequencer, heating coils, fan relay and the safety control switches. Over time, relays can fail or stick together from electrical currents, causing a circuit to stay closed and constantly supply power. Check to make sure your air conditioning fan relay or control board fan relay is. Some split systems will have a transformer for the heating and a transformer for the air conditioning system. And any electrical device with a plug on the end — be it a light, a fan, or a blender — can be plugged and unplugged, as easily as you would with a simple power strip. Theres not much you can do other than killing the power to the furnace itself. If the fan didn't come on, you'd still be warm inside. Five years ago, I replaced that relay with this updated solid state model (RLY02807). Terminal Quantity: 4. The fan switch is on auto, not on, and even tried a different thermostat and had the same results. After 22 years, the original Fan Relay went bad (condition: relay stuck in the closed position causing fan to run 24/7 as if in Fan ON mode). See Below for what we offer. Car wiring question. I have a few questions: #1) Is the blower regulator the problem? #2) Can. The fan clutch is what pulls air through the condenser (radiator for the ac is in front of the real radiator). It’s not actually part of a furnace but part of the air conditioning system. If the actual room temperature is below what your thermostat is set for. When the ignition switch is turned to the OFF position, the voltage from the IP junction block WSW/RFA fuse to the RFA module is removed. Most likely I'll have to break it up and install a new blower fan. 9 Tdi sport), but apparently even same year models can have no high-pressure sensor, in which case it may be your regulator/compressor and a bigger price tag to fix. Replacing a furnace condenser or evaporator coil costs $600 to $2,000 or more. Bottom Row, Left to Right Radiator Fan High Speed Relay, ABS Control Relay with 10Amp Fuse, Window and Sunroof Relay Blower Motor and Motor Control Unit Check The factory Service Training book on the Digital Climate Control system used in the 1986-88 5000T/Q, "Digital Climate Control for the 1986 Audi 5000" has some great design and theory of. HVAC Troubleshooting: How to Fix An HVAC Compressor That Won’t Turn On. Fan cycle control: This is normal if this type of control is based on pressure. Set the thermostat to HEAT and the fan to AUTO. If it says cooling fan relay, it’s talking about the relay that controls the radiator fans. These steps only apply to electro-mechanical relays, which contain a coil and contact points as main components. A transformer, usually 24 volts, energizes the contactor which has a coil built into it. One time I had that issue and it ended up being that I had the 'fan' setting set to 'on' rather than 'auto' so the fan was on all the time rather than just when the A/C was running, lol. Locate the fan relay. On the 78's its in a plastic relay block and the ones I dealt with the block was so badly melted you could not get the main contacts out. Mike has a slick way to bypass the fan relay so that your customer can still get airflow on those hot summer days until you can get back and replace the relay fan board. Radio (MCM) Instrument cluster (MCM) Clock. The relay you swapped out is in fact the cooling fan relay, which is a multi-use relay, Porsche number 141 951 253B (worth about 5. If it doesn’t then you probably have loose or burnt wires in behind the relay or you may need a new fan relay or circuit board. AC contactors can wear out and are at the top of the list of common air conditioning service failures. I know there is other speed likes low and medium which is indicated in the dash controls but it remained on high speed regardless of the position of the control knob. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. What would cause the blower motor to be stuck on high? It does not matter if I turn the fan speed knob to 0,1,2,3, or 4, it will not change speeds or shut off. Wondering if this could be the blower motor. 2: Engine Compartment Main Fuse & Relay Block Identification Courtesy of Toyota Motor Sales, U. When the coil of the relay is de-activated, it acts like an inductor, trying to suppress current change. This schematic shows that on #4 fan speed (Hi), a relay cuts off the resistor pack return that would go to the blower motor on speeds #1, #2, and #3 eliminating it from a normally functioning circuit on speed #4. Generally wiring is in a functional triangle. The fan clutch is what pulls air through the condenser (radiator for the ac is in front of the real radiator). Now runs finewill keep an eye on it and report if it fails again. 2L engines) 34. In 940 cars, remove the same low-pressure switch connector at the receiver-dryer and jumper it: current comes directly from terminal 10 of the MCC control. Model ARUF36C14AA Serial 1206526906 Ran a call yesterday on this Goodman air handler fan was running 24/7 except when there was a call on w for Aux heat the fan would deenergize and the heat stips would fire for a few seconds unit the limit kicked out and then the stips would fire agin after the limit closed. Five years ago, I replaced that relay with this updated solid state model (RLY02807). Thermostat turns on Gas burners correctly. When the fan switch moves to any speed it energizes the coil in the relay which closes the contacts in the relay. You should hear a slight hum from the compressor and the air coming off the unit should be warmer than the ambient air entering it. Cause: A software concern is currently being investigated by Jaguar Engineering. Use a quality 5A fuse. That is definitely one possibility. It is important to make sure the heating elements and the blower are switching on and off in the correct cycle. This video will show you how to properly diagnose your blower by using the multime. See Below for what we offer. " When the thermostat switches on, a low-voltage signal energizes the appropriate relay. After 22 years, the original Fan Relay went bad (condition: relay stuck in the closed position causing fan to run 24/7 as if in Fan ON mode). Try unplugging the fan connector, relay or fuse. Cigarette lighter relay. @bhurry turn your AC off and see if the fan still stays on. I have located the relay switch that looks almost impossible to access. AutoZone couldn't cross reference the Relay I brought in, so I'm going to call that back in. The manual may refer to a blower relay, an AC relay, or a cooling fan relay. Just keep in mind that many modern cars use electronic relays. 1/8 - 25 HP. Cut out the required opening by first drilling a pilot hole and cutting along the dashed line using a jig saw or tin snips. The heat and or air will work and cycle on and off as normal. Testing Automotive Relays Explained Defective Relay. In most cases if you miss diagnose the electrical problem and buy a new relay and it doesn’t fix the car, you’re stuck with the part you didn’t need. There is no external relay involved, just a control box mounted on the fan assembly itself. That delay is either on the board or on a separate relay, depending on the model of furnace. -The core of the radiator is welded in vacuum brazing furnace, no epoxy. Look for terms such as a blower, AC, or cooling fan relay on your schematics to point you in the right direction. Two for constant 12v power and one for a signal from the ECM to tell it what speed is required. Seat heater relay, rear. As a result, the contactor is not engaging automatically so in order to have cold air in my house I have. Average repair cost is $420 at 59,650 miles. Blower fan keeps running: A failing sequencer may have a "stuck" contact and keeps a heater coil and the fan and running. Anti-thef (door open sig. 1988-1993: The two-speed fan runs on low. Fan cycle control: This is normal if this type of control is based on pressure. I replaced the OEM Valeo switch with a NAPA/Echlin piece ($36) and, sure enough, one pair of switch contacts (uppermost) were toasted. Choose from our selection of low-current relays, signal relays, high-current relays, and more. This happens when the switch simply fails to shut off the fan after the burners have stopped and the air exchanger is sufficiently cool. In most cases if you miss diagnose the electrical problem and buy a new relay and it doesn’t fix the car, you’re stuck with the part you didn’t need. Pump Relays & Fan Controls Sort by Featured Best selling Alphabetically, A-Z Alphabetically, Z-A Price, low to high Price, high to low Date, old to new Date, new to old The Micro-Air PRP Pump Relay was our very first high-volume production product. Step 1: Locate the relay. If it too much for you call a pro. When the relay is activated the AC condenser fan is switched on so that it can keep the AC. The duty cycle. These problems can keep the blower fan from blowing enough air out of your vents to keep you cool. When Fan is switched from Auto to ON, Fan goes to High Speed. If something were to fail and short, the chances of an interior fire are significantly reduced if a relay is utilized to allow the higher voltage switching occur in the engine compartment. hvac industry leaders America’s Most Trusted® HVAC System. Every furnace that has an R wire also has a C wire. The same type of “Thermal Runaway” problem is also likely to cause failure of the ordinary “cartridge type” in-line fuse holders—It’s why we have supplied the 18gauge Fusible Link in our Relay kit. The two fan fuses (30A and 40A) are in the same location. Each fuse looked good and showed good by my meter. Tighten the screws. So about a month ago or so the fan relay stuck open on my upstairs GOODMAN Heat Pump and today now the downstairs unit did the same thing. the only means of turning the air handle fan off is from the circuit breaker. Most likely I'll have to break it up and install a new blower fan. In heating and cooling these relay/contactors are used to turn on high voltage components such as motors, compressors, and other high voltage components. Right Fan Motor connector disconnected. 0L 2014, GM Original Equipment™ Engine Cooling Fan Motor Relay by ACDelco®. Is the fix listed above something that would also work for my Malibu? not sure on a 2012 Malibu BUT I would drop /remove the blower motor and see if its got burned up wiring and connectors etc at the motor connector and resistor assy next to the motor. The contacts of a relay or contactor must make good direct contact when energized for the device to function properly. I disconnected entire thermostat and also replaced with a new thermost but the problem remains. F75 – F76 (20A) Trailer socket. The most likely problem is an internal short with your blower relay. But another problem that occurs just as frequently from a faulty relay is that the heating elements and the blower fan will refuse to shut off. When the coolant temperature reached the threshold, (about 107°C) the control unit switched the "change over relay" and the "right fan relay" to earth. On a 1995 Chevy Pickup it is located behind the glove compartment. The heat and or air will work and cycle on and off as normal. Spend Management. The fan switch {often referred to as a fan relay} has either contact points that open and close or a bimetallic strip which allows electrical current to flow to the fan motor. I have a 2001 Solara, and the heater/AC fan ONLY works with the fan control switch in the high position. Here's a pic of the resistors Which fan speed you choose determines which resistor gets "used" by the voltage coming from the relay. Each fan motor's connector has two wires coming out of it. Install snap-acting HVAC relays from Grainger in any position for remote control of air conditioning, heating and ventilation systems. An AC relay will remain contact closed due to mechanical inertia and a little mechanical hysteresis and, the fact that an alternating north and south pole both attract the relay armature. When the compressor cycles on, it also feeds a line to the condenser fan relay, running the fan. If it says cooling fan relay, it's talking about the relay that controls the radiator fans. Turn the air conditioning unit's breaker off at the main electrical panel. The DC coil has a freewheeling diode for protection against back EMF & de-energizing the coil. They are produced at top tier facilities. I have the fan on constantly for a day or so and discovered that the fan would no longer turn off. Tighten the screws. Gas Heat cycles on and off correctly and keeps temperature per the setting on the thermostat. 2) Heater Blower relay is behind centre console (where Fitted), 3) Auxiliary Heater relay is under drivers seat (where fitted). The circuit for high speed involves the relay to be closed. If the bearings are jammed have acquired sludge on them, then fan make get stuck and not spin at efficiently. You can now buy select products directly on TE. Figure 4 shows the wiring for this circuit. HVAC Heating & Cooling: Chattering Furnace Contactor: Jan 7, 2017: HVAC Heating & Cooling: HVAC - both blower and fan will not start, contactor not pulling in. Check for Line voltage across BR contacts. When the fan motor continues to run continuously long after the heater burners turn off, the most likely problem is a fan switch has become stuck in the closed position. Glove compartment lamp. Hard Start Kit for slightly stuck Air Conditioner Compressors; Hard Start Kit for stuck Air Conditioner Compressors; Heat Pump Outdoor Motors and capacitors. Your owner's manual (!) should have a fuse/relay legend for the fuse box (es). Putting dc on an ac coil should work fine but be prepared for the resistance to be low. Over time, relays can fail or stick together from electrical currents, causing a circuit to stay closed and constantly supply power. Your fan motor relay is operating properly, turning off the blower, however the compressor relay is stuck on, leaving the poor compressor running (the hum noise) without any cooling fan. 5 uf MFD 370 or 440 VAC Oval Run Capacitor PW-7. Anti-thef (door open sig. I replaced the blower motor resistor, but that did not resolve the issue. The reason for this is that the relay could. First, the air conditioner may not be the problem. AC Fuse and Relays The fuse is an easy and obvious item to check whenever there is a problem with a component. When Fan is set to Auto, Fan goes to Moderate Speed. In 940 cars, remove the same low-pressure switch connector at the receiver-dryer and jumper it: current comes directly from terminal 10 of the MCC control. I checked for stuck sequencer and no/nc contacts on th time delay relay for the blower. When power is fed to the relay the blower comes on immediately for the air. This will in return will put more stress on the motor, which could also lead to the motor being burned out. February 2, 2014 - If your fan no longer runs at the high speeds it used to, then it's probably worn out from years of use or has other issues that limit airflow. The first and simplest area to check is the fan unit on the inside air handler. So if your furnace blower is turning on and off when the furnace isn’t in a heat cycle, it usually means the fan limit switch is defective. If you never touched your computer it wont go bad. Note: The 1N4148 diode is connected in a odd fashion for a reason. Opened it up cleaned contacts all seems fine. The two fan fuses (30A and 40A) are in the same location. Overloading the breaker/relay, then when it resets kick back on again? Not sure if these trucks have relays on the fan or not?. How Your Fan Normally Works. The low and medium-speed relay has gone bad, and I think it's all integrated into the whole thing on a Cruze. By wiring these outlets to the relays we created a plug-and-play device that works on both ends. The connectors that can be removed from the block fit the new relay and the ones that were stuck had to be cut and replaced with new crimp ends. And if you have allergies, it's better to have your fan running continuosly to filter more air anyway. But another problem that occurs just as frequently from a faulty relay is that the heating elements and the blower fan will refuse to shut off. Remove the access panel with a screwdriver. The PCM will actuate the fan relay whenever the A/C clutch is engaged regardless of coolant temperature and vehicle speed. 50 AMP Breaker. 85 86 30 87 87a. This fan stays off, even when water temps are near max. Relays open and close electrical circuits to various parts of your AC system, most notably, the fan. If the fan still does not turn off, there’s a malfunction with thermostat or the furnace’s fan relay switch. I dont have auto screen demist and heated screen is off. Problems like a fan clogged with dirt, a dead motor, a loose fan belt or a stuck wheel can all cause your blower to not work properly. The pop up. An AC contactor is a $25 mechanical relay that uses low-voltage power from the thermostat to switch 220-volt high-amperage current to the compressor and condenser fan. Use the schematics included in your owner’s manual to locate a path to the relay. Tom and Ray say she can either fix her fan the right way, or take the cheap and easy way out--using paperweights to keep her stuff from blowing away. If the relay is stuck in the ON position, it'll slowly drain your battery. MAX AC has the same results. If fan is set to Auto, fan stays on even after gas heat has cycled off. That is definitely one possibility. Your evaporator coil needs air to blow over it to complete your AC's cooling process. If it too much for you call a pro. AutoZone couldn't cross reference the Relay I brought in, so I'm going to call that back in. I did the actual wiring in the air handler since the duct and installed fan were located nearby. The blower motor is crucial to the proper functioning of your HVAC system. 120v AC @ 50/60 Hz coil. This happens when the switch simply fails to shut off the fan after the burners have stopped and the air exchanger is sufficiently cool. Last month the AC computer went erratic and my fan speed was jumping up and down automatically even if I kept it at 1, 2, 3 or 4, then my temp reading went from F to C and. Our Smart Search accepts the following: Year, Make, Model followed by the part type Example: 2010 Ford F-150 Air Filter; Part number Example: 9004. My Gas Furnace Comes On And Off Too Frequently • Adjust the thermostat heat anticipator • Troubleshooting a Thermostat • Replace dirty air filter How to inspect, repair or replace the Blower Fan Belt on a furnace: Regularly inspect blower-fan belts for any sign of damage and replace the belt if it’s damaged. This area includes all components and systems both mechanical and electronic that are related to a vehicle's heating and air conditioning system. AIR IN LOOP: Air in the piping can block water flow and seriously impair heat transfer efficiency in both heating and cooling modes. The AC starts and stops as required, I tried the heat as well and it comes on and off no problem, but the fan will run 24/7. If the thermostat is not calling for cooling, there will be no voltage present. Locate the fan relay. As a result, the contactor is not engaging automatically so in order to have cold air in my house I have. Find Hayden Electric Fan Controls 3647 and get Free Shipping on Orders Over $99 at Summit Racing! Make sure that your cooling fans turn off and on with Hayden electric fan control kits. If it does not, continue on. How Your Fan Normally Works. Many small, inexpensive and easily replaceable parts are prone to breaking down. Hard Start Kit for slightly stuck Air Conditioner Compressors; Hard Start Kit for stuck Air Conditioner Compressors; Heat Pump Outdoor Motors and capacitors. In some models one relay is used to supply fan power; another may be used to control fan speed. When the fan motor continues to run continuously long after the heater burners turn off, the most likely problem is a fan switch has become stuck in the closed position. 1-1/2" x 3" x 2-3/4"H. Go to the thermostat and turn it to OFF and the fan to AUTO. These problems can keep the blower fan from blowing enough air out of your vents to keep you cool. This will be a set of contacts that are normally open.