# Yet another blower fan stuck on high



## pfarrelli (Jul 25, 2006)

The blower fan on my 2001 Pathfiner LE 4WD with electronic climate control is stuck on high. There are many posts regarding this issue but none have exact solution.

Even when I manually change the fan speed or turn entire unit off, the fan stays on high.

Basically I have read it is probably the "fan control amplifier". From what I understand this is the same as the "fan resistor" found behind the glove box (according to a post, you need not remove the box change the part).

However I called the dealer and they said that when system is off and the fan continues to run, then it is not the resistor. 

Then I call yet another dealer and they asked for my VIN. They then said it is not the FCA as it doesn't have one and I need to change the "AC conrtol Amplifier" (which costs $380+ dollars).

I also read today that I may be able to disconnect the positive lead on my battery for five minutes to let the computers reset. I have yet to try that today.

What I was wondering is if I could get some info on exactly WHAT my setup is for my year make model and type of system and what could be causign the problem. Do I have a resistor or not? etc. etc.

Thanks

Pf


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## dirtdog (Jun 20, 2006)

Nissan must have A/C problems with this system
2005 Pathfinder LE
My A/C went out - A/C condenser they said.

I just got mine back today and when it is on the auto setting it runs full blast

when I go to manual I can turn it down ?

Thank goodness it is still under warranty for me.

Will wait and take a long drive with it as the drive back from the dealer is only 20 minutes. If it stays on full blast I will take it back to the dealer for a fix .. and have some answers for you I hope .


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## pfarrelli (Jul 25, 2006)

Only problem is mine is on FULL all the time. No manual manipulation helps at all. Just high.. High and fast as can be.


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## dirtdog (Jun 20, 2006)

Sorry guy other than this bump I can't help you. Took it for a drive and it worked fine.


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## KSpider (Feb 9, 2006)

reading this post makes me think my AC is messed up as well (2006 LE)

Ill have the temp on 76 or 77 and its only 75 out and the blowers are going full blast on auto, Ill hit auto again and it will turn the fans down. been doing this for a few weeks now... seems like the auto turns the fans up to cool the car off but doesnt turn them back down...


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## dirtdog (Jun 20, 2006)

I've never had a vehicle with climate control 

that I did not have problems with.

So it doesn't surprise me with the Nissan's .

I have had Cadillacs
Ford T Birds
Name it the climate control - auto always was fubar.


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## KSpider (Feb 9, 2006)

Well, I have never had any problem with climate control with any car I have had... until this one... though, not a huge deal (yet)


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## Delirious (Jan 13, 2006)

pfarrelli said:


> The blower fan on my 2001 Pathfiner LE 4WD with electronic climate control is stuck on high. There are many posts regarding this issue but none have exact solution.
> 
> Even when I manually change the fan speed or turn entire unit off, the fan stays on high.
> 
> ...


So have you resolved this problem?
I am interested as this is happening on my '97 Maxima. Blower fan motor run on high regardless of the switch setting including off! btw this is not a climate control system.


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## pfarrelli (Jul 25, 2006)

Delirious said:


> So have you resolved this problem?
> I am interested as this is happening on my '97 Maxima. Blower fan motor run on high regardless of the switch setting including off! btw this is not a climate control system.


Sorry I have not. Still blowing. I figured it would blow most of the time over the summer so why bother. Mabye soon but I fear I need to replace the entire climate control unit on teh dash (according to Nissan dealer). About $350 parts. I'd do it myself.


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## Ron 97 Pathfinder (Sep 16, 2006)

pfarrelli said:


> "The blower fan on my 2001 Pathfiner LE 4WD with electronic climate control is stuck on high. There are many posts regarding this issue but none have exact solution."
> 
> Hey, I have a '97 pathfinder (auto air - climate control feature) with the same problem...I came here looking for info as I just spent a couple of hours in my driveway messing around. Here is what I do know...mine started last winter and to get a break from the fan noise I would pull the relay block. (I replaced the relay but still had the same problem) The relay block is located behind the ashtray near the fusebox. There are 3 large relay's (1.5"x1.5") and it is the one higher and in the center. Removing this will cut the power to the fan. (By the end of the winter I got pretty good at removing it and replacing it while driving.) Anyway we pulled the glove box and found the resistor. There was a wire connector running into it with a white plastic cap held in by 2 screws. When you pull it out the base is a metal cast housing with finger-like probes (I assume to read the temperature in the airbox). Inside there is a small curcuit board with the resistors and this board is connected to a NEC chip. I have not been able to find the exact chip online yet but a quick search found a close number and the description was a "high speed switch". I took a picture of the part and sent it to a dealer and was qouted $246.00 (Can). My Pathfinder is rough and I don't plan on keeping it long so I don't want to pay the dealer price so here are the options I have considered...Aftermarket...no luck, junkyard...no luck in my area, find Nec chip...need to search some more, Add a new switch...tonight I wired a 3-way toggle switch directly to the coupler that used to connect to the resistor assy. I was able to turn the fan on and off for $3.99. Now I need to find out how to connect a resistor to the switch to have a reduced speed setting._|_If anyone has any ideas on how to set this up or find the prpper part at a resonable price...please let me know._|_Blasted in Ontario!!!


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## pwhjyh (Jul 9, 2015)

Was this ever resolved? I have a 2001 Pathfinder LE which has the same issue. Manual does nothing, the fan always runs at high


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## pfarrelli (Jul 25, 2006)

Yes. Resolved. Very easy too. Remove the glove box. To do this pull the two pins out where the glove box hinges. Behind the box is a heat sink with a small circuit panel on it. Replace that entire unit. I bought one and swapped it out in the parking lot. WOW what a difference not to hear that damn fan on full blast! I waited a year before making a concentrated effort to fix it. Once I did I realized it was an easy fix and I should have done ti months earlier.


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## pfarrelli (Jul 25, 2006)

It is a blower motor resistor.

Here is what you will see behind the glove box:
http://i.ytimg.com/vi/MTrFBfMv_T4/maxresdefault.jpg

Here is what the thing looks like:
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/$%28KGrHqZHJEUFBggwK%28kmBQc06Zb5L!~~60_35.JPG


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## bubba198 (Jan 15, 2020)

I agree with everyone that mentioned blower motor resistor. I have Pathfinder 2002 LE and suddenly while driving the blower started running at 100%. Nothing could kill it except turning OFF the ignition. None of the AC controls had any affect on it. I pulled the fuse just so the thing doesn't drive me nuts and researched the symptom. Most hits were around blower motor resistor so I ordered it, swapped it, that's what it was!

I find it funny that everyone calls is blower motor resistor. It has nothing to do with being a resistor. The part is a high power MOS switch (a semiconductor thing) which translates the PWM signal from the electronic fan control unit into driving current for the motor. Since I've literally never tinkered with cars I took the opportunity here - the PWM is at 9.5v with periods between 4ms to 90ms based on the 4 stages of the LE's electronic fan control gradients. That's all. Super simple design only if the MOS thing didn't blow up for me but hey it worked for 18 years so I am happy!


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## smj999smj (Jan 1, 2006)

If it's manual HVAC, it's called a "blower resistor." If it's automatic climate control, then Nissan calls it a "blower amp" or "VBC," (variable blower control).


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## Judy D (Feb 7, 2020)

bubba198 said:


> I agree with everyone that mentioned blower motor resistor. I have Pathfinder 2002 LE and suddenly while driving the blower started running at 100%. Nothing could kill it except turning OFF the ignition. None of the AC controls had any affect on it. I pulled the fuse just so the thing doesn't drive me nuts and researched the symptom. Most hits were around blower motor resistor so I ordered it, swapped it, that's what it was!
> 
> I find it funny that everyone calls is blower motor resistor. It has nothing to do with being a resistor. The part is a high power MOS switch (a semiconductor thing) which translates the PWM signal from the electronic fan control unit into driving current for the motor. Since I've literally never tinkered with cars I took the opportunity here - the PWM is at 9.5v with periods between 4ms to 90ms based on the 4 stages of the LE's electronic fan control gradients. That's all. Super simple design only if the MOS thing didn't blow up for me but hey it worked for 18 years so I am happy!



Where did you purchase the new part?


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## smj999smj (Jan 1, 2006)

bubba198 said:


> I agree with everyone that mentioned blower motor resistor. I have Pathfinder 2002 LE and suddenly while driving the blower started running at 100%. Nothing could kill it except turning OFF the ignition. None of the AC controls had any affect on it. I pulled the fuse just so the thing doesn't drive me nuts and researched the symptom. Most hits were around blower motor resistor so I ordered it, swapped it, that's what it was!
> 
> I find it funny that everyone calls is blower motor resistor. It has nothing to do with being a resistor. The part is a high power MOS switch (a semiconductor thing) which translates the PWM signal from the electronic fan control unit into driving current for the motor. Since I've literally never tinkered with cars I took the opportunity here - the PWM is at 9.5v with periods between 4ms to 90ms based on the 4 stages of the LE's electronic fan control gradients. That's all. Super simple design only if the MOS thing didn't blow up for me but hey it worked for 18 years so I am happy!


For those with manual HVAC, it's a blower motor resistor (or, "resistance"). For those with auto climate control, it's called a blower amp, or a "VBC" (variable blower control).


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## smj999smj (Jan 1, 2006)

Judy D said:


> Where did you purchase the new part?


Rockauto.com is a good place to purchase aftermarket replacements. If you want a genuine Nissan part, go to NissanPartsDeal.com (they are in Massachusetts) or CourtesyParts.com (which is in Texas).


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