Blower Motor constantly turning on and off on its own

[CanuckQx4]

My blower/heating system has developed a little glitch where it turns itself on and off while blowing air at any speed setting. Which is getting very annoying in this cold weather.

Its not like it turns on or off for minutes at a time, its almost constantly switching on and off, it will switch on and then before it has time to even get to the full speed setting it would turn off again. The odd time it will work fine.

Would this be a part starting to fail, or a wire connection problem you guys think??

Appreciate any help!

[yeldogt]

Is the display staying on?

The ACC has a very common fault -- the resister/ fan controller fails and the blower will run full blast and then not at all. The display stays on and works normally.

The controller is mounted behind the glove box -- I replaced mine in about 15min -- you can get them online for around $100.00.. Change the cabin filter while you have it opened up.

[CanuckQx4]

Yes the display works perfect

I wouldnt say it goes full blast all the time though, if I have it on low, it kinda sounds like it goes on and off the low setting etc etc

[yeldogt]

Not many parts to the system ......... 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. I think it just fails .... like it does in every other Nissan. That's why I said to get a new filter -- plus it is so easy to replace. 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. The motor is also sitting out in the open

I bought the control from a dealer in the midwest on e-bay -- he had about 10 of them and was the cheapest price ....came in the Nissan box.


Both of my Pathfinder are 2002's -- some of the earlier cars actually had a blower motor that was prone to fail ... when the motor failed it would short out the controller ........... so that is the only thing that you need to look into. If you think it may be the motor you can get a "kit" from Nissan that includes the updated motor and the newest controller ............ The "kit" is actually cheaper than the motor itself on many dealer sites ..... I think it was about $220.00 .......so it is a good deal if you need the motor.


I believe the Q only came with ACC -- both mine are ACC ......... although the manual system has a different controller with similar failure rates.

[fueler]

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....

it ended up being a poor connection at the battery terminal !! It took me several annoying hours of troubleshooting to figure it out. Not sure why the battery terminals affected the climate control (only).... Electrical gremlins suck! Replaced them with new gold terminals and cleaned the battery posts and i've been fine ever since.

My situation was probably unique, but it might be worth checking for you...

[CanuckQx4]

Well I dont quite just wanna buy this controller and assume its the problem. As you said your display was turning off and mine is not. The cabin air filter is fairly new, less than a year.

My battery connections are pretty minty aswell, definetely clean and secure

[yeldogt]

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.

This is one of those NIssan parts that is not a matter of "if" it will fail it is really "when" will it fail.


If you know how to use a multi tester you can check the system output and also jump the blower motor to see if it is working properly.

[CanuckQx4]

Do you have a picture of the fan controller? I cant figure out exactly which part it is when Im looking at everything here

Theres a pathfinder in the junkyard close to me I can check it out tomorrow

[yeldogt]

Since I don't know where you are looking this is the part number ....... 27761-70T03 ....... obviously you need to cross reference your year. 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. Don't pay much for the used part ..... it too my be original. I have replaced them in both of my current 02's and a previous 01.

[CanuckQx4]

and you think that module being bad would cause my problem?? Even though the screen stays illuminated even when the blower is cutting in and out??

[ARKQX33V6]

Canuck, your blower needs power are you saying this blower turns on with the main ignition off or on?
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.

The speed range of blower is dependent on the control setting. As a new part expensive, can you locate a used supplier?

[yeldogt]

Canuck -- The system has only three main parts for the blower on the ACC control -- you do have a Q with the automatic system ...correct?

I can't see your car or hear the motor so it is up to you to understand the system. If the display is working correctly then we can assume that the power to the ACC is working correctly -- these units rarely fail so we make the assumption that it is sending out power to the blower system. Now ....if it is blinking/ flashing/ dimming as the motor changes speed then the ACC is part of the problem.

So ......we figure that the display head unit is working ..... the system has only two other parts ........ the module and the blower. Both can cause the problem and both are known to fail .......especially the module. I'm not sure what else to tell you. It is what it is and they cost what they cost.

If you don't know how to test the motor to make sure it is working correctly then you will have to take it to someone -- this will cost you more than the most likely part to fix the system --- and you will still have to purchase the part that is causing the problem. The motors can fail -- and when they fail they overheat the module and it burns out -- so you need both many times with a bad motor. But since your motor is working and you did not report any strange sounds -- I am assuming that the most common failure point in the system is the problem ... that is the module.

When mine failed a few months ago I had to make a decision -- do I buy the module or the kit with both module and motor. Mine stopped working all together ... so my motor cold have blown -- but is sounded fine prior to not working. I ordered the new module only .....figuring that if I heard any strange sounds from the motor I would have to buy the kit ...... so I would end up with an extra module (the kit is cheaper then the motor alone?). These are the risks you take when you do your own work ... we are not always correct in our guesses. But even with the extra parts purchased -- still cheaper than taking it to someone.

[CanuckQx4]

I think Ill try and find a used module to start.

Appreciate you typing that out ALOT, it helped, I know Im stubborn, like you said, I just dont want to waste money, Im a poor college kid and maintenace like this isnt always in the budget