Hvac Blower Motor Works Intermittently

(NOTE: older style resistor from OP). Then, regardless of speed setting, it will revert to no blower action, then all by itself, it will start up again. So I'm wondering if it's not a stuck relay. For example, I will set it to 3/4 power yet nothing is coming out from the vents…. Yesterday though, the blower didn't work yet again. If I raise the temp on the thermostat, the furnace ignites and then shuts off, then a few seconds later the blower motor starts to cycle warm air. If I stop a second time, it may or may not start up again. 6L is working intermittently. Let's see if we can pinpoint this intermittent fault No fancy tools required!. I don't intend to touch the car myself because frankly, I don't even know where to begin and wouldn't want to try. However, they did require a lot of electrical energy. Today I was all set to take my Truck back to Ford Service center today and wouldn't you know it the AC and blower worked perfectly. on for three seconds, off for three seconds; on for three seconds, off for three seconds, etc. "How to Troubleshoot a Furnace Blower That Runs No Heat. on the way there, the blower worked fine. I have a 2006 Dodge Ram 2500 (5. heater & ac blower not working Dec 1, 2011 #1 any clues?? the heater and ac works but the fans not blowing. I have a 2000 Honda civic ex. Took my climate controls out and the fan continued to work, ended up pulling the 40amp fuse in the engine bay to shut it off so I don't kill my battery. A furnace blower motor that stops pushing warm air out is not the same as a blower that is forcing only cold air into your home. The blower works sometimes at all speeds and sometimes it won't work at all. Why does a Hyundai Elantra blower motor work only intermittently at all speed settings? Evidently the motor is not making a proper contact because the connection to the blower motor and resistor might be loose or might even have burnt. This will be due to either a loose connector at the blower motor or a dead spot in the motor. Thanks for your question about your AC. It works for a while, turn off the engine then when I come back, it stops working. 2003 L300 intermittent blower L-Series Tech manual HVAC controls. every once in a while it will work correctly for a few hrs then starts on and off. The fan works fine for a day or two then refuses to come in. They do chit the bed, and can present with the issues reported, in this thread. It's possible for the electrical failure of the blower motor resistor to take out one or both of these fuses as it melts. Blower Fan Works Intermittently There is a blower motor. I have a 2015 RAV4 LE and the AC blower intermittently works. I've been having a nuisance issue with the blower in my '06 Ram 1500. Some times it comes on and some times it doesn't. Sometimes it's after a minute, sometimes it's after 20. If the connector is not making a good connection, your blower motor may work intermittently or not at all. Buy OCPTY A/C Heater Blower Motor ABS w/Fan Cage Air Conditioning HVAC Replacement fit for 2002-2008 Dodge Ram 1500 2500 3500 4000/Jeep Grand Cherokee: HVAC Motors - Amazon. If you start at the blower motor, and check resistance in the circuit, you will find the problem in no time. It's possible for the electrical failure of the blower motor resistor to take out one or both of these fuses as it melts. (Bentleys) Something I have done on older cars is to access the blower, turn the ignition and fan to on and spin the blower with a pencil. A/C Blower Problem - It Works intermittently. It seems like the furnace does kick on occasionally, but the fan will not. When it does work the fan does work on all speeds. So it appears that the blower motor must be corroded just enough to have some resistance on initial start up. As the day heated up when I got off the lake my AC/Heater blower would not work. Anyway it doesn't matter, you called it on both accounts. If dinking around with the knob affects it on any speed in any way, I'd say it's the switch on yours, too. I have struggled with my heat/AC for a few weeks now. Check the furnace flame for a complete blue color. Why does my heater/air conditioning blower just work sometimes? When I turn the blower switch on, sometimes it works other times it does not, when it works it works correctly on all speeds, when it does not, nothing comes on. When the truck was brand new back in 2009, there was a problem whenever the automatic transmission was put into park. This may be related to a faulty blower motor or blower motor relay. Blower Motor on AC/Furnace working intermittently. We took a 200 mile round trip today. Ive been having problems with the blower motor working intermittently. Best Answer: no the blower motor should never do thatthis normally indicates there is some kind of problem with the blower motor or there is some componet that controls the fan motor in the air handler that is going bad. No matter what you call it, how much it’s going to cost to replace your blower motor depends largely on 2 factors:. Here are the symptoms and what I've done so far:-Sometimes it works and sometimes it doesn't. Blower Motor Problems on GM Vehicles General Motors Climate Control Panel. The resistor (module) is located next to the blower housing and the wiring harness is connected to the blower motor. I picked up a modern 1/6 hp motor and a belly band, and, many small adjustments later (with no shortage of cursing. The following assumes your blower motor is failing on all 4 speed positions. The blower motor is usually to blame when the climate control fan suddenly starts working intermittently or only at one speed. I'm getting intermitting 'fatal error: file not found' errors building C++ application using either gcc 4. The issue is that my blower motor operates intermittently. brought it to dealer and they just called me and told me had to replace blower motor and needs new heater core. [Air Conditioning] Blower Motor or Blower Motor Resistor Ive been having a intermittent issue. Air is cold so I know the system is. SOURCE: 2012 Equinox the ac fan works intermittemtly. They drive Explorers, and of course the officers have the heat or AC running all the time. 6L is working intermittently. Fan is CanBus (computer) controlled. They are two different mods that help with performance in similar and in different ways. I figured I'd wait until it finally died before replacing it. I've basically run into a similar issue with my '00 TJ. The blower motor motor works intermittently. The blower on my 87 560SL works intermittently. When off, it may stay off for days, or sometimes will turn on after hitting a bump or slamming the door shut. If the fan is not working I can hit under the passanger side dash and it will start working. If the motor won't work on high, then it's probably the motor. Probably not a bad idea but if it were me I'd remove the OE Blower first and bench test it to see where it was squealing and whether the dried up bearing could be lubed and saved. The dirt in it however may be much more than you think. Had it in my garage yesterday and it just works some. I need some help here in fixing my AC problem. Best of all, it's cheap, and is only 2 or 4. The resistor (module) is located next to the blower housing and the wiring harness is connected to the blower motor. This is the device responsible for applying the correct voltage to the blower motor, based on driver input from the vehicle’s manual 4-stage fan setting on the IHKS (Integrated Heating/Air Conditioning) controls. My question, what does the schematic look like for this motor? It's a 3 terminal motor so I suspect it has an. My blower motor stops working almost every night! I have no issues during the day. 9 L Cummins diesel). My fan indicator shows the fan working at the proper speed, but no air is coming out. The blower motor is usually to blame when the climate control fan suddenly starts working intermittently or only at one speed. It worked for about 2 weeks and now it stops intermittently until yesterday when it has stopped for good. I'm having a problem with my Broan Electric furnace lately. When the resister of the blower motor starts to fail, the motor operates only intermittently. Will start working sometimes when I am driving. Why does my heater/air conditioning blower just work sometimes? When I turn the blower switch on, sometimes it works other times it does not, when it works it works correctly on all speeds, when it does not, nothing comes on. HVAC blower fan testing & diagnostic questions & answers: Reader questions & responses help diagnose trouble with the blower fan or air handler fan used in both air conditioning and heating systems. Thanks for the reply. - Occasionally works turns on and off - Slamming the right hand side passenger door would temporarily fix the problem - Tapping on the blower motor metal housing with the handle of a screw driver would temporarily fix the problem - Wiggle the blower motor power source - Blower motor turns on and off - Wiggle the housing - Blower motor turns on. Then all of a sudden it started blowing full blast, while the recirc, ac, rear defrost button lights all came on and were flashingthen it all turned off. When the truck was brand new back in 2009, there was a problem whenever the automatic transmission was put into park. No matter what speed it's set to. Is there a relay that is maybe not working or is the blower motor maybe going out. Blows ok for days then nothing. When I have my fan on, it sometimes sounds like its slowing down and stopping. there is a blower motor relay and a 40amp blower motor fuse ( #109 ) both in the under hood fuse box. When I turn the knob on the dash, I do here a click in the area of the blower motor in the passenger. I have been having an issue with I guess the blower on the air conditioner on my 2004 mustang. I keep a spare motor and resistor pack around just in case but have not had another issue. When this happened, the customer said that the Electronic Throttle Control, ABS, Traction Control, and sometimes the 4WD lights would come on. Ac blower motor works intermittently and now does not work. It seems like the furnace does kick on occasionally, but the fan will not. also found burt wire to resistor connector. I have struggled with my heat/AC for a few weeks now. I also checked the salvage yard motor directly with the battery and no problems. Blower motor works intermittently, HELP! My 98 750 heater blower motor works when it wants to. When I turn the knob on the dash, I do here a click in the area of the blower motor in the passenger. if the blower is shot it will sometimes work this way enough to tell you it is getting power. The resistor broke and was not letting the fan operate correctly. It worked for about 2 weeks and now it stops intermittently until yesterday when it has stopped for good. If dinking around with the knob affects it on any speed in any way, I'd say it's the switch on yours, too. At first this is intermittent, then later pretty much constant. I have followed everything that is said on this thread and everything is fine. The condenser will kick on but the blower will not so I have to turn the unit off. When I let off the gas the blower comes back on. I purchase a new fan motor, unplugged the wire harness leading into the current (Mounted) blower and plugged into the replacement motor. The fan speed can be changed either by switching the blower resistor resistance mechanically, using a rotating lever, or electronically by the air conditioning system. Keep the blower motor clean. Homepage › Old Car Air Conditioning › Chevrolet AC Blower Control Problems. I had to have mine replaced. When I have my fan on, it sometimes sounds like its slowing down and stopping. I have a 2006 Honda Odyssey. With loss of high speed fan, other fan speeds (lower) operation became intermittent, works after jiggling blower motor wire bundle at connection point on blower motor resistor. Symptoms: Car turns on with AC on, blower on full, both temp dials set to coldest (62) blue mark, vent either on manual or automatic. If u put it to out side air and are cruising at a good speed u feel alittle air blowing through but the fan isn't blowing out air. The test light should stay lit up the entire time, if the light ever goes out that indicates an open in the armature. (Bentleys) Something I have done on older cars is to access the blower, turn the ignition and fan to on and spin the blower with a pencil. If I start out my trip the blower fan is working fine. The blower switch and resistor are on the ground side of the blower motor to ground. 8L V6 engine that produces 105 HP with a 4 Speed. Plugged it in and the blower spun up while sitting on the floor. So as you see it is a 4 year old problem. My girlfriend's 2008 Cobalt has recently had an intermittent blower motor problem. The Cool is wired to the "high" speed setting on the blower motor. It's also possible for the resistor to become worn out and need replacement. I have a 2015 RAV4 LE and the AC blower intermittently works. If the fuse that controls the blower motor starts acting up, or even worse—gets blown, then the blower motor will work intermittently or not at all. Re: Intermittent blower motor operation Nov 07 2016, 11:01pm Well I have the blower motor resistor on the way from Amazon, and I have some fancy aviation electrical contact cleaner, so I'll try replacing the resistor and cleaning the rheostat and see how that works out for me. The Cool is wired to the "high" speed setting on the blower motor. Disconnect the wiring connector from the blower motor to make sure there isn't any corrosion or connection issues. Once again thank you for the tip. Blown fuses. After getting home I tried multiple times after disconnecting my trailer. It is not possible to repair the blower motor; if it is. The blower motor forces air to circulate within the vehicles interior. The resistor is located very near the blower itself and is bolten down to a heat sink. Seems to be improved by jiggling the wires under the dash. Sometimes, but not always, the blower fan for heat and air conditioning does not work. I was told this is due to the drainage pipe being clogged. Kit Includes. there is a blower motor relay and a 40amp blower motor fuse ( #109 ) both in the under hood fuse box. I tried the resistor plate to no avail on my '88. Any ideas as to what is wrong? On 2016-07-15 by (mod) re: fan motor cuts out then turns back on on hot days. I've run a jumper wire from power to the motor bypassing the controls and the resistor. I had to have mine replaced. This Honda Accord is having trouble with the HVAC blower motor. This is an intermittent issue, doesn’t always happen but when it does, the fan shuts off and the burners continue until the heat safety shuts down the whole unit. Rear AC Blower seems to be fine. Depending on what kind of car you have, it should be a pretty simple fix. Any ideas why this would happen?. If there is no power then the control relay may be bad or you may be missing the signal to the relay. Re: Intermittent blower motor operation Nov 07 2016, 11:01pm Well I have the blower motor resistor on the way from Amazon, and I have some fancy aviation electrical contact cleaner, so I'll try replacing the resistor and cleaning the rheostat and see how that works out for me. 6L is working intermittently. If it doesn't, nothing I do will make it work. the motor has an internal overload that shuts it down if it gets to hot or pulls to many amps. Any help would be greatly appreciated!. Wouldn't work using the on screen buttons either. I have a 2003 V70 wagon. I can see the AC display react to increasing or decreasing the blower speed, but nothing comes out. The standard unit has a resistor The Deluxe/automatic A/C (the one where you set the temp number and the car maintains that temp) will have a control module. My wife told me today that the blower on the heater storeds working today just as if you turned off the switch. I've basically run into a similar issue with my '00 TJ. If dinking around with the knob affects it on any speed in any way, I'd say it's the switch on yours, too. Average failure mileage is 114,000 miles. i assume the wire molex on rear side of blower motor. Hopefully, the blower motor simply blew a fuse. Once again thank you for the tip. Blower for A/C and heater is not working (or at best working intermittently). With that said, if the blower motor doesn't work at all it's also common to find a defective blower motor relay. Blown fuses. It also seems to go on and off when I hit bumps in the road. Ive been having problems with the blower motor working intermittently. Hey guys went on a call, forced air furnace, blower motor marathon motor, no capacitor, intermittently, motor tries to start and hums, give the pulley a little push and she takes off. Recall: HVAC Blower Motor Fire Risk and coolant and it works for a few weeks. Find many great new & used options and get the best deals for Genteq EON Hd08 Programmable HVAC Blower Motor and Module at the best online prices at eBay! Free shipping for many products!. Step one would be to check fuses.   As similar types of fan motor assembly appear on many Mercedes models the replacement of the carbon motor brushes is much the same across the range once the motor is removed. And if the fan motor doesn't turn, and the system is switched on, the lack of cooling air to the blower resistor can cause that to burn out pretty quickly. It will occasionally turn on after about 2-3 minutes of driving. motor or capacitor? I'm not sure if it's the capacitor or the motor. It's also possible for the resistor to become worn out and need replacement. This can be annoying, but troubleshooting is easy. Details: With the ignition key in the ON position, the tech verified the HVAC blower motor is not working. Recently though, it's gotten to a point where sometimes, the blower motor would completely stop working. Front blowers don't work when back ones do. I stop it then restart on 4 works althought on 3,2,1 works as well any clues what could cause this?. 5 HVAC System Sounds You Don't Want to Hear If your HVAC system is making funky noises, contact a professional to investigate before it turns into a large repair bill. The 2010 Ford Escape has 6 problems reported for intermittent ac failure. This seems to happen mostly when the temp is over 80 F (25 C), which of course is when I need it. Symptoms: Car turns on with AC on, blower on full, both temp dials set to coldest (62) blue mark, vent either on manual or automatic. I have been having an issue with I guess the blower on the air conditioner on my 2004 mustang. After you've completed all the previous steps, you will need to ascertain if the problem is with the blower motor itself. I tried to get my wife to bring the car directly home from work today, but she has a class at the gym. Before troubleshooting any HVAC system, it’s a good practice to become familiar with the components and wiring diagram, check for and follow any on board diagnostics (fault codes in the manufacturer’s control board). Blower motors can go bad as well, though they usually won't work on start-up, rather than stop working while running. Will either replace it or, in the interim, will have to grease the shaft of the motor. They drive Explorers, and of course the officers have the heat or AC running all the time. Now that you understand what it is, now we can discuss how to properly troubleshoot the X-13 motor. Heater(blower) works intermittently. The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. The fan speed control is on the power cord, and that doesn't seem to affect restarting it that I can tell. I picked up a modern 1/6 hp motor and a belly band, and, many small adjustments later (with no shortage of cursing. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Ac blower motor works intermittently and now does not work. No matter what speed it's set to. RE: Blower Motor IP: Logged Message: Hello , I also was having intermittent blower motor cut out until it all stopped working (and smelled like melting plastic). I tested the bottom sequencer but afaik it is good. Sometimes it's after a minute, sometimes it's after 20. We went to leave, turned on the AC and no fan!!! The compressor was on, and when I was moving, cold air would ooze from the vents. The second problem SOUNDS like-- The Infamous Blower Motor problem. i was scouring google for solutions at the time so i could be associating damn near anything with the BMR. It would intermittently blow on high, with no means to adjust it, then work normally for a few days. If it will work on high but not at the lower speeds, then it's the resistor pack. I was told this is due to the drainage pipe being clogged. my 2010 nitro heat and ac stopped working last week. I have a 1997 Chevy Blazer 4. However, it only worked for about 20 minutes and the blower motor stopped working again. Details: With the ignition key in the ON position, the tech verified the HVAC blower motor is not working. The fan starts up fine, runs fur just under 60 seconds and shuts down for about 20 seconds and turns on again repeating the process. After you've completed all the previous steps, you will need to ascertain if the problem is with the blower motor itself. It worked for about 2 weeks and now it stops intermittently until yesterday when it has stopped for good. Fortunately, it is a relatively easy problem that can be fixed in your own driveway. Started off in auto and moved to low fan speed on the way there. The switch for the blower motor will not blow under any position. You will see a motor sitting on top or next to a larger blower wheel connected by a fan belt. When are you folks going to address it with gm since we as the people have some much invested in them. Crazy, I just replaced a blower in an elderly, tiny electric furnace yesterday. Blower motor also may run with the key off. It had a 1/6th hp motor and a mount that would only work with that motor, the motor was so old it had been made in the US. Click the link above for more details. If you start at the blower motor, and check resistance in the circuit, you will find the problem in no time. I would focus my attention more on the blower motor, Item #20 & test as previously advised. Our central air conditioner units will have problem as it ages. Any ideas?. If it will work on high but not at the lower speeds, then it's the resistor pack. The strange thing is it will work perfect for a week, then act up for a day or two. replaced it. (This can be a problem at -30) They had it all day, and tried everything to get it to do it again, but as expected, it worked just fine. Symptoms of a Bad or Failing Blower Motor Relay. ) If a blower motor breaks down, an HVAC professional can replace it for $400–$600, including parts and labor. The blower motor for the heater and A/C started making a noise in late 2010 that got worse over time, and the Toyota dealer replaced it under warranty just 4 days prior to me writing this review. As I mentioned before it was an intermittent problem and it hasnt stopped working yet but if it does a resistor replacement will be in order. The blower motor is usually to blame when the climate control fan suddenly starts working intermittently or only at one speed. It's located inside the dash, often on the opposite side of the steering wheel or inside the engine compartment on the firewall. The change in resistance then limits the current through the motor, which dictates the speed at which the blower fan works. Now that you understand what it is, now we can discuss how to properly troubleshoot the X-13 motor. vehicles were almost unheard of. It worked for about 2 weeks and now it stops intermittently until yesterday when it has stopped for good. I have not personally inspected my truck, but the blower motor is controlled by an electronic Motor Speed Controller (MSC) and not a resistor banks. The blower motor may be burned out or worn out. I recall during my research that others have had random elecrical problems "clear up" when replacing the BMR. There are few things to inspect and confirm before you directly replace blower motor. However, the front blower makes a dying noise when the cold air is on, and sometimes just doesn't do anything at all. This resistor can become damaged over the years and cause intermittent operation of the blower motor. Kit Includes. We went to leave, turned on the AC and no fan!!! The compressor was on, and when I was moving, cold air would ooze from the vents. They will draw from the same evaporator, so the system is working. Intermittent HVAC Blower cuts out and comes back on I'll be trying. The best part is, our Chevrolet S10 Blower Motor products start from as little as $6. I would think that if it was the blower motor it would not work at all. I can still feel heat and cold coming through the vents when I turn the AC on, but the it doesn't always blow air. Car problem(s) with the 2008 HONDA RIDGELINE. The resistor is located very near the blower itself and is bolten down to a heat sink. It seems like the furnace does kick on occasionally, but the fan will not. When it comes to your Ford Explorer, you want parts and products from only trusted brands. Driving down the interstate, I can barely feel cold air coming from the vents but the blower is still not working. This can certainly be a pain for the Ram owner, but does it also signify a bigger … Dodge Ram Blower Motor Works Intermittently Read More ». 2007 Toyota Corolla AC Blower Issues It might be on its way out and work intermittently. SOURCE: 2012 Equinox the ac fan works intermittemtly. Then all of a sudden it started blowing full blast, while the recirc, ac, rear defrost button lights all came on and were flashingthen it all turned off. 5 to 3 minutes after your thermostat calls for heat and should turn off several minutes after the heating cycle ends. However, it only worked for about 20 minutes and the blower motor stopped working again. The blower motor will only operate if the blower motor switch is in any position other than OFF, and the ignition switch is in the RUN position. Furnace then goes off without blower motor engaging 3. This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. wouldn't have anything to with the blower motor working intermittently. Front blowers don't work when back ones do. Gas that enters the furnace is ignited by the pilot light. From what I've gathered, all these issues (hot wiring, melted plugs, burnt out switches/resistors) with the HVAC appear to be symptoms of one core issue: the blower motor is going out, and should also be replaced. The furnace blower blows hot air through the duct system of the home. I noticed the fan was not blowing any air through the vents. On mine I greased the bearing on the bottom of the motor (which was filled with dirt and grime also) and blew all the crap out with an air compressor. The blower motor motor works intermittently. First thing I did was scanned the truck. However, the front blower makes a dying noise when the cold air is on, and sometimes just doesn't do anything at all. The blower motor is usually to blame when the climate control fan suddenly starts working intermittently or only at one speed. com FREE DELIVERY possible on eligible purchases. I have not had time to check it out yet but I was wondering if this an issue with blower motor itself or the resistor or switch or whatever it is called. 11 new and used Chevrolet Corvette cars for sale in Tampa, Florida at smartmotorguide. The rear blower works fine. Submission Guidelines: First search the links below for specific info. Click the link above for more details. and the blower motor switch and resistor is changed as one part and that is the resistor you were looking at, that's all. Testing begins at the HVAC fuses in the driver's side fuse box that is located behind the dash end cap. I had 2004 with the same problem. The first time the problem occurred, I thought immediately, it was the blower motor transistor, so I replaced it, as well as the cabin air filter. So i got back under my dash and pulled the motor and tested all my connections and the voltages again. If the blower is NOT running, then press the AC. If power is getting to the blower motor, but the motor does not run, the motor may be burned out. [HVAC] Furnace Intermittently Fails to Light My old Amana Air Command 80 has been acting up recently, where I will come home for instance, and it will be sitting there just running it's draft. vehicles were almost unheard of. 2 running in Windows Subsystem for Linux (WSL), when. And there's even a small chance that there might be a problem with the AC control head that sends the signal to the AC blower control module. This Honda Accord is having trouble with the HVAC blower motor. Buy Goodman GMH80803BN 80,000 BTU Furnace, 80% Efficiency, 2-Stage Burner, 1,200 CFM Multi-Speed Blower, Upflow/Horizontal Flow Application. Replied by K24A4 on topic Intermittent AC Failure (2008 Saturn Vue XE) Work and travel has kept me from being able to work on this problem - but the car has "acted up" the past two days. - Occasionally works turns on and off - Slamming the right hand side passenger door would temporarily fix the problem - Tapping on the blower motor metal housing with the handle of a screw driver would temporarily fix the problem - Wiggle the blower motor power source - Blower motor turns on and off - Wiggle the housing - Blower motor turns on. Depending upon the motor design, it can be a start or run capacitor. It has an SF-25 furnace. A/C Blower Problem - It Works intermittently. Second, make sure that power is getting to the blower motor. I can see the AC display react to increasing or decreasing the blower speed, but nothing comes out. After engine warms up, when I press the gas pedal the A/C blower turns off. For more information on how your furnace works, here is a great article from Popular Mechanics: How your heating system works. Here's how to replace the blower motor in your A4, and make your driving experience comfortable once again. They will draw from the same evaporator, so the system is working. As I mentioned before it was an intermittent problem and it hasnt stopped working yet but if it does a resistor replacement will be in order. A blower motor resistor or a blower motor control module is the part that controls the speed of the blower motor. I had to replace my blower motor in January. Now spin the blower motor by hand. Have had two mechanics look at it, one being the Dodge dealer. The two-state blower works fine with my furnace, moves hot air just fine. If there is an open in the armature the fan may still spin but it is failing and can be the cause of intermittent operation. What are the likely problems. [Air Conditioning] Blower Motor or Blower Motor Resistor Ive been having a intermittent issue. Car fan AC only works on high Replacing the Blower Resistor 2008 Toyota How to Test Vehicle AC/Heat Blower Motor to Tell if BAD How to notice bad resistor in Toyota blower or fan. The rear AC works just fine. Thanks for your question about your AC. For example, I will set it to 3/4 power yet nothing is coming out from the vents…. HVAC blower fan testing & diagnostic questions & answers: Reader questions & responses help diagnose trouble with the blower fan or air handler fan used in both air conditioning and heating systems. Then I'll stop once and it will come back on again. I purchase a new fan motor, unplugged the wire harness leading into the current (Mounted) blower and plugged into the replacement motor. 5 HVAC System Sounds You Don't Want to Hear If your HVAC system is making funky noises, contact a professional to investigate before it turns into a large repair bill.