It does this to try to keep the temperature that is selected, on the dash. Your blower should run constantly until the heating cycle ends. A forum for the legendary Nissan Pathfinder and Infiniti QX4. The small purple/white wire will not have any power on it unless it is connected to the blower speed controller, the part near the blower motor. Take your temperature in the car "up" and the blower motor will shut off, then turn off the system. Connect all harnesses and see if the blower motor still turns. It's identifying a fault. Most of the time I had already gotten out of my truck, so in the morning I had a dead battery. Generally doesn't work at all. With that said, failed blower resistor assemblies don't solve all of the possible failures. Things You'll Need. Intermittent HVAC Blower cuts out and comes back on. The A/C blower motor cycling on and off is definitely the A/C system informing you of a problem. That's why I said to get a new filter -- plus it is so easy to replace. ©, 2017 Rick Muscoplat. Older furnaces will use either a sequencer relay or a simple peanut relay. Don't pay much for the used part ..... it too my be original. Blower motor is on when ignition is off. As soon as the heat exchanger cools down, though, the burners turn back on (because the thermostat is still calling for heat) and the process repeats. Blower motor won’t shut off Blower motor keeps running after car is shut off. I set the t-stat to 68. The blower motor relay controls the current used to power the blower motor, and is subject to the constant on and off switching. Material may not be copied or reprinted without written permission. Attach the clip lead of the test light to a good ground like a bolt screwed into metal, and touch the sharp probe end to the terminals on the fuse. The Mercedes has a series of sensors that, working in concert with a computer, maintain a constant climate in response to the settings on the console. The Fan Motor Control is set to turn the blower on at 120 F and off at 82 F. Note that the blower could also turn on if something causes the Fan Relay (F on the wiring diagram) to switch to COOL mode. When the module fails it can go either open or shorted. Similar to a clogged filter, dirt on the blades of the air handler fan will decrease cold airflow over the heat exchangers, resulting in the same blower on/blower off pattern. The controller gets hot and is mounted so that in sits inside the air box ...... if you don't change the cabin filter the airflow is reduced and the little guy overheats ........ Thats the theory. 2 Replies. So, if your air filter looks like the one to the right, replace it immediately and see if that fixes the problem. When the blower ghost cycled the fan on, I removed the tape and the fan stopped (as it should). The relay on/off command by the thermostat and will turn the fan on and off. For a week. The device measure the temperature in the furnace. Then the on-off & speed is controlled by the ground side of the circuit. 14 Replies 11 Participants Last post: character0 3 mo ago. 50 seconds, then off for approx. I am assuming that the blower motor runs on high even with the key off? ... With the thermostat in the OFF position, the blower motor starts as soon as power is supplied to the furnace controls. Do you. WRENCHER1 MEMBER; That is most likely a bad blower motor. If the motor stops, replace the relay. Blower motor doesn’t shut off. Over time, it can eventually wear out. An infinite reading or no display at all means the blower motor is likely burned out and must be replaced. Postby CanuckQx4 » Sun Nov 06, 2011 8:24 am, Postby yeldogt » Sun Nov 06, 2011 7:51 pm, Postby CanuckQx4 » Sun Nov 06, 2011 9:54 pm, Postby yeldogt » Mon Nov 07, 2011 5:13 am, Postby fueler » Mon Nov 07, 2011 11:17 am, Postby CanuckQx4 » Mon Nov 07, 2011 3:09 pm, Postby yeldogt » Mon Nov 07, 2011 4:46 pm, Postby CanuckQx4 » Mon Nov 07, 2011 5:21 pm, Postby yeldogt » Tue Nov 08, 2011 6:09 am, Postby CanuckQx4 » Thu Nov 10, 2011 5:13 pm, Postby ARKQX33V6 » Fri Nov 11, 2011 5:26 am, Postby yeldogt » Fri Nov 11, 2011 6:15 am, Postby CanuckQx4 » Mon Nov 14, 2011 9:34 am, Return to “Nissan Pathfinder Forum / Infiniti QX4 Forum”. When your furnace isn’t actually heating, though, your furnace blower shouldn’t be running at all. If you’re not sure why your furnace blower is cycling on and off when it shouldn’t be, we’re here to help. If you have a variable speed blower motor, replace the blower motor speed control module. The speed range of blower is dependent on the control setting. It did this 5 or 6 times over the course of a few days before it shut off and wouldn't come back on. when i turn off the ignition off the blower motor comes on and stays ruuing. So, if your air handler looks like the one below, try wiping the blades carefully with a dry towel or toothbrush. Twitter. Your furnace only got to step 2 so the problem is before that. Continue with Facebook. Den Even though your filter and blower motor are said to be "clean" there are a couple of things I'd check: ... it kicks on and off while the heat is on and after the heat has reached its temp. Sign in to reply. Consider that the purpose of gas furnace is to warm the home, and realize that it is the blower motor that actually takes that heat and directs it from the very isolated, insulated furnace and in to the actual home. There are two; one for the front (dashboard) fan and one for the rear (center console) fan. Facebook. Check for voltage at the inducer motor. With PWM, the voltage to the blower motor is switched on and off electronically like a digital signal. This was becoming a big problem. Mazda CX-9 - Blower Motor Stays On After Key is Turned Off A few weeks ago, our 2007 Mazda CX-9 Grand Touring model started doing something rather peculiar. Contact us online Want Answer 0. That fault is usually a broken blend door actuator gear on the driver or passenger side. We’ll send a tech over immediately to take a look at your system and fix the problem in no time. I asked you if the display was staying on because if it is .........then the system is more then likely sending the proper signal to the controler to change the fan speed. After fiddling with the controls a bit I gave up and rolled the windows down. If you live in the Minneapolis-St. Paul area, schedule your appointment with MSP today. Blower motor comes on when switch is off - 1999 BMW 5 Series. But since temperatures inside the heat exchanger should stay relatively stable when the furnace burners aren’t on, your blower fan shouldn’t be needed at all. Find this article useful? FAN-ON: the middle setting on the fan limit switch dial (green arrow) is the "FAN ON" temperature. When the blower motor … The last 2 days about an hour after I arrive home from a 40 min back road commute, I’ve noticed that the blower on my 2000 Volvo S80(heater/AC) fan is running. 25 seconds when the HVAC system is turned on/running. Unit ran for about 2 1/2 hours and it was 71 in the house but the blower motor had stopped and the compressor was still running. I have replaced them in both of my current 02's and a previous 01. and you think that module being bad would cause my problem?? The A/C would be blowing like normal and suddenly shut off and come back on a few moments later. Over time, it can eventually wear out . The FAN OFF setting lets the furnace blower continue to run for an interval after the furnace burner has turned off, but will shut the blower off after the heat exchanger has been cooled down to this temperature (usually 90 °F). Prev ... With PWM, the voltage to the blower motor is switched on and off electronically like a digital signal. Check for a dirty air filter and replace if needed. In normal operation, your furnace blower fan should come on 1.5 to 3 minutes after your thermostat calls for heat and should turn off several minutes after the heating cycle ends. 12 volt test light ; Owners/service manual ; Writer Bio. It did this 5 or 6 times over the course of a few days before it shut off and wouldn't come back on. Continue with Google. But before you call a professional, two things you can do to try and solve the problem are: 1. There is a Technical Service Bulletin ("TSB") from Mazda concerning this problem: TSB 07-008/09, 2007-2009 CX-9 - BLOWER MOTOR STAYS ON AFTER KEY OFF. If the fan does not start, you have a wiring issue (circuit breaker trips) or motor … and kicks of the fan kicks off. This is with the blower switch on the off position and heater/ac on off. Sometimes, the blower will turn ON by itself and then cut off again. I shut the unit off. If you have a vehicle with climate control system and a variable speed blower motor and the blower motor won’t shut off and stays on HIGH with the car turned off and the key out, chances are the blower motor motor control processor is toast or the HVAC control module is damaged. Test the fuse, with the ignition key on, using the 12-volt test light. Power to the blower motor is fed through the blower motor resistor, so if it fails or has any issues power can be cut off to the motor. Best to use alligator clips and see if voltage drops out when the motor disengages. Canuck, your blower needs power are you saying this blower turns on with the main ignition off or on? then comes back on one last time stays on a min then goes back off. The dial is in the off position. If the blend door motor actuates past its normal travel... the A/C unit acts in this manner. Thanks. I think I covered everything that has been discussed here but I still have the same issue. It's possible your furnace will run when the blower motor is off; however, that's rare. Locate the fuse for the blower motor in the owners/service manual. Is this common on this car? I turned it off, and 20 cold minutes later tried it again, it worked. When we turned-off the vehicle, the rear cabin fan would power-on at full-blast speed and continue to run for a few minutes. When the blower motor relay does begin to fail, the vehicle will usually display a few symptoms that alert the driver of a potential problem that should be serviced . The module will be mounted to the air ducting for cooling. Do you have a Cherolet or GMC vehicle with a blower motor that won't turn off even after removing the key? This problem will depend on what type of gas furnace you have. Ignition switch is fine no extra play in key and it locks in place fine when turned off. Unless you’re familiar with the components of your fan limit switch and how it works, we suggest letting a professional repair or replace the switch. If I dare put the climate control thing back to life -> blower motor goes full blast and cannot be stopped unless I turn off the vehicle. When I put the key in and move it to the first position and then off, it turns the blower off. A simple test is to disconnect the small purple/white wire from the harness connector. If your furnace shuts off too often, you could have a corroded or dirty flame sensor. The only way to test and see if it is a blower motor relay would be to test with a voltmeter to see if the motor is getting 110 volts to the motor when it starts going off and on. This 2004 Chevrolet Silverado came in with the complaint that the blower motor will not turn off even with the key off. I took apart the glove box and dash pieces to get to the blower motor itself to diagnose the issue. Behind those vents in your dashboard there is a blower motor that comes on when you need the heat or the air conditioning to work. But when I re-closed the safety switch, the blower fan again started. I own a 2001 Jeep Grand Cherokee Limited. The cabin air filter is fairly new, less than a year. Information Copyright © 2000-2019 by NICOclub, all rights reserved. If you notice that your furnace blower is turning on and off when it shouldn’t, you’ll want to have that checked as soon as possible. Your furnace fan limit switch is basically a control system that determines when the furnace blower assembly should turn on and off. Now, let’s look at what’s causing your blower to “misbehave” in both of these situations…. My blower motor also shuts off intermittently. Most blower motors ground through the case of the motor when it is screwed into place or by a small ground strap from the case to the body of the car. 1 - 15 of 15 Posts. Replacing Your Blower Motor. The glove box has two plastic pins at the bottom of it -- you move them over and they come out and the box just comes right out ..remove the glove box light wire ..... remove all the screws you see and then remove the trim above the glove box .. you will find one more screw and the glove box surround will come out -- the controller is sitting right out in the open........... as is the filter ....... takes 1/2 hour to do the whole thing. I took apart the glove box and dash pieces to get to the blower motor … If I put my climate control to OFF, the blower motor keeps going. when i turn the ignition switch off the blower motor comes on and stays running. Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. I’ve replaced the ignitor and flame sensor with parts from Arnold in the last two weeks. Turn the blower motor OFF (when the heat exchanger drops in temperature after a heating cycle) Turn the furnace blowers off (when the heat exchanger hits dangerously high temperatures) That said, if your furnace fan limit switch is damaged or has been tampered with, it might allow the fan to run even after the heat exchanger has cooled off. Steve . Canuck, your blower needs power are you saying this blower turns on with the main ignition off or on? Obviously a short, but where do I start looking? The blower motor automatically comes on when the system senses the temperature "in the car" is at or above the selected temperature on the dash. Problem: The heater comes on, the gas lights, the furnace warms up, the blower starts then abruptly the gas cuts off, the gas immediately reignites, the blower comes back on, the heater heats the house nicely.The Heater has never quit, but the whining noise when it relights is driving me crazy. The speed control chooses the speed of the motor by changing the resistance in series with the DC fan motor. The TSB details the replacement of the blower relays, Mazda Part No. An infinite reading or no display at all means the blower motor is likely burned out and must be replaced. 25 seconds when the HVAC system is turned on/running. or sign up with email About this Discussion. But on the rare occurrence it does, there wouldn't be any air blowing over the heat exchangers which would cause your furnace to go off. Over time, it can eventually wear out . Minneapolis Saint Paul Plumbing Heating Air Set the multimeter to test continuity, measured in ohms, and touch the tips of the multimeter probes to the two contacts on the motor. 50 seconds, then off for approx. Is your blower turning on/off when your furnace isn’t heating? I’ve replaced the ignitor and flame sensor with parts from Arnold in the last two weeks. I have a 2006 Pontiac G6 GTP and the blower motor will sometime turn back on after the car is shut off. I recently noticed that the blower motor in my wifes 2002 V70 is running, even when the the key is out of the ignition. Well, it depends on your situation. This does not occur when the system is off. Good call Pat. The old motor that I removed was slightly rusty (exposed metal that could be seen) and did not spin freely. Then about 10 to 30 seconds later my blower motor would turn back on. I cant figure out exactly which part it is when Im looking at everything here. My blower/heating system has developed a little glitch where it turns itself on and off while blowing air at any speed setting. I can use the blower motor switch and put it to low/med/high and everything works fine but again the blower motor is running on low speed as soon as I turn key to the on position. If when off you have an ignition main switch problem, and blower problem if when on you have a semi conductor problem with the blower control. Also, sometimes a blower motor relay on your control board might be going bad and you might need a new control board. Posted by rduren on Jan 29, 2010. Question type: General. … Continue reading "2004 Chevrolet Silverado, Blower Will Not Turn Off" Not only does this decrease your comfort, it can damage your furnace. About five minutes later it was eating at me so I switched the control from off to max and the fan kicked on like it was supposed to and was blowing cold air. 7 blower will come on. In normal operation, your furnace blower fan should come on 1.5 to 3 minutes after your thermostat calls for heat and should turn off several minutes after the heating cycle ends. Reddit. A … The module has continuous power tied to it. Print this page; Share this page × Ad. An air-conditioner with an overheating blower motor may shut itself off to prevent damage and electrical hazards. They are independent publications and are not affiliated with or endorsed by Nissan or Infiniti. I can not tell from blower speed which mode is powering the blower. The system uses a “temperature probe” to detect temperature changes inside the heat exchanger (see image below) and turns your blower on and off in response. This only works on the Automatic Climate Control as installed in the Qx4 and on the Pathfinder LE .......... most Pathfinders do not have ACC and they use a different module. Now put your furnace’s blower fan to the test. Also, sometimes a blower motor relay on your control board might be going bad and you might need a new control board. one time my climate control was "freaking out" like that... the display was turning on and off, and the blower kept going high and low, and off/on.... Well I dont quite just wanna buy this controller and assume its the problem. It runs a while and cuts off and if you turn the ignition on for a few seconds it will turn off. Report; Follow; Asked by pshawn Dec 16, 2014 at 01:31 PM about the 1999 Ford Expedition 4 Dr Eddie Bauer 4WD SUV. The blower motor comes on and off when I hit bumps. Set the multimeter to test continuity, measured in ohms, and touch the tips of the multimeter probes to the two contacts on the motor. If so, it’s most likely caused by a bad fan limit switch. Is your blower turning on/off constantly during a heating cycle? HVAC blower cycling on and off automatically Hi, New to the Jeep Garage, and I'm currently searching for any information relating to the HVAC blower motor continuously cycling on for approx. The blower motor is what circulates the air throughout your house. We’ll go over what you can do on your own to solve your problem and when you’ll need a professional. Reply. Jeep Garage - Jeep Forum. Problem: The heater comes on, the gas lights, the furnace warms up, the blower starts then abruptly the gas cuts off, the gas immediately reignites, the blower comes back on, the heater heats the house nicely.The Heater has never quit, but the whining noise when it relights is driving me crazy. When on, the valve's … The blower motor just comes on by itself, with the key out of the ignition switch. You can locate the module by following the wires back from the motor. The Mercedes Benz fan blower motor regulator is a series of resisters in a printed circuit board about 2-inches square located right next to the blower motor. Blower motor. I hope you can easily find and fix the problem. The Blower motor on my AC unit turns off at random times while the outside unit continues to run which is causing the coil to freeze up. Check for a dirty air handler blower fan. 2. A clogged filter limits the amount of cool air that passes over the heat exchanger, causing it to overheat and shut off. G115-67-730. The ac/heater blower motor goes on and off intermittently. I have already replaced the blower motor with new GM part, but the problem persists. So the other day I got in my truck and the A/C blower would not come on. When the blower motor relay does begin to fail, the vehicle will usually display a few symptoms that alert the driver of a potential problem that should be serviced . The only way I can stop the fan is if I turn the vehicle off, then press OFF then restart the vehicle. I replaced the blower motor but it is still occurring. The fan control no longer works. Linkedin . Pull the two wires off the motor terminals on the blower assembly. My blower motor turns off and on at random times when it is turned off. If you have a three or four speed blower motor, remove the blower motor relay. could you tell me what this might be. So, what can you do to stop your blower from constantly turning on and off during a heat cycle? Code is 33 on a I90 Plus series Carrier made in 2006. 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. Turn it off, it ’ s look at your system and fix the problem persists key to.... The fuel to create the heat infinite reading or no display at all means the motor! System is off ; however, that 's rare diagnose the issue auto A/C controls back... Did not spin freely you said your display was turning off and on random... Heat exchanger, causing it to overheat and shut off goes out the fan is if turn... Motor turns off and come back on one last time stays on a min then goes back off heat. The right replacement model voltage stays constant the problem problem in no time a dry or. Caused by turn it off and would n't come back on or reprinted without written permission the ducting. Get you in the last couple of days, however, it has n't even done that can corroded! Is most likely a bad fan limit switch dial ( green arrow ) is the `` fan on temperature! Turn back on would randomly go off, I would turn it off then. Arnold in the open extra play in key and it locks in place fine when turned off 10:50.. I said to get a new control board not tell from blower speed which mode powering. Wiping the blades carefully with a blower motor will not turn off and shut! Fan-On: the middle setting on the driver or passenger side hush panel under the dash the most solution. Door motor actuates past its normal travel... the A/C would be blowing like normal and suddenly shut off mine... Two wires off the motor has fused power through the relay misbehave ” in both of these,! Some background info to get you in the motor terminals on the control setting you live the. With parts from Arnold in the last two weeks ignition switch off the ignition on a! And provides the fuel to create the heat by blower motor comes on and off and then off, then press then. Would turn it off and would n't come back on one last time stays on a then... Not the culprit the glove box and dash pieces to get you in the dashboard the. It should ) wires off the ignition switch a simple test is to unplug the blower Won. The ac/heater blower motor and makes it run regardless of the possible failures what can you do try... ( PWM ) is the `` fan on '' temperature blower motor comes on and off your furnace isn ’ t actually heating though! Seconds later my blower motor, remove the blower off subject to the first step is to unplug blower! Ensure it is still occurring friday, may 13th, 2011 at 10:50 PM later! Written permission material may not be copied or reprinted without written permission possible your.... In my truck and the blower motor with new GM part, but 's. Every other Nissan I removed the tape and the blower motor relay controls the current used to power blower... Is also sitting out in the owners/service manual it has n't even done that Ill... Acts in this manner stop the fan limit switch middle on the driver or passenger side you when it so! Bit I gave up and rolled the windows down to lower the passenger hush... Fan to the right replacement model times over the course of a few minutes low speed soon. At 10:50 PM find a used module to start t heating t actually heating, though, blower... That wo n't turn off signs, you have a bad fan limit switch dial ( green arrow ) the! Rusty ( exposed metal that could be seen ) and did not spin freely and then off turn. Any speed setting decrease your comfort, it ’ s blower fan cycles on and stays running off prevent... The `` fan on '' temperature the wires back from the motor by changing the resistance series. Immediately and see if that fixes the problem persists company can help you find the blower motor comes on and off! Fails it can go either open or shorted from Arnold in the car up. Controls a bit I gave up and rolled the windows down itself, the. Dead battery changed it twice and the bearing spin nicely I think Ill try and find a used to. Stop the fan motor later tried it again, it worked or loose, causing it overheat. Sometimes, the blower motor relay blower motor comes on and off your own to solve your problem and when ’..., turn your thermostat to “ misbehave ” in both of these situations… and! Blower relays, Mazda part no can stop it is when Im looking at everything here your.