This post was a real help and a very worthwhile piece of work; Thank You Andrew 224. This is really better that Factory issued maint. manuals or even after market CD's because of the pictures. I was able to change the filters and Fan Control Amp in about 30 minutes whcih probably saved me $500 in Dealer charges in a 2000 Infinity QX4. 7/26/2009Bob Farr

To give credit where it is deserved, I posted the instructions. Other members added the pictures. And then someone else even figured out how to repair the amp. for a couple bucks. But we are all here to help. It's a team effort. That's why I like this forum. We help each other out more than we flame each other.

Andrew

Changing the blower motor was very easy using the instructions above to remove the glovebox/paneling and took about 30min. I found a motor online at https://www.am-autoparts.com/ for $55.55 free s/h and it arrived in2 days!

A big thank you to everyone here, especially Andrew and Solara. Who knew that the fan blowing on high was enough to send one over the edge. I spend close to 2 hours a day in my car and that fan was driving me crazy.

I have a 2003 Pathfinder and bought the parts at Courtesy. Delivery slower than I would have liked, 4 business days, total cost for fan control amp and filters was $156, delivered. The 2003 Pathfinder is also one of those where you have to cut out the hole for the filters. If I had done my homework and realized this ahead of time I would not have installed them. Trying to cut a clean hole in the plastic so that the filters fit nicely was a PITA. I have done without them all this time could have continued without them. Unless you have severe alergies or other reasons to want them I suggest doing without.

The fan on my 2000 Pathfinder SE only blows on high. I followed the instructions from one of the previous post, but once the glovebox was removed I could not locate the Fan Control Amp. There is an obvious location where the amp should be located, but there is a molded plastic insert in its place. I traced the wire harness from the fan switch but could not follow it all the way. Is there another place were this FCA could be located?

Also, when I ordered the Fan Control Amp I also purchased the cabin filters. There are no provisions in the housing to accomodate these filters. I read in a previous post that it may be necessary to cut slots in the housing in order to use these filters. Is this indeed the case?

Thanks for all the great help so far.

I am going to assume that since you do not have the holes already cut out for the in-cabin air filters (from the factory) then you have manual HVAC controls. Now, assuming you have the manual dial-type HVAC controls, your issue is not the fan control amplifier (since the manual HVAC system does not have one), your issue is the fan resistor. This means that the resistors are fried and you need to replace the entire resistor unit.

Do you have the digital (automatic) heating/air system or do you have the three dial (manual) heating/air system? If it's the latter then the above paragraph applies to your vehicle. If it's the former, then everything I have said here does not apply.

You are absolutely correct in that the HVAC controls are manual. Is the resistor unit difficult to change out and where is it located? Thanks!

John2000Path wrote:You are absolutely correct in that the HVAC controls are manual. Is the resistor unit difficult to change out and where is it located? Thanks!

The blower resistor is actually very simple to replace and only takes about five minutes and no dis-assembly is required! If you look under the glove box area you can see the blower motor. The blower resistor is located on the other side of the blower motor (on the firewall side) and it's held in with two screws. You just have to remove those two screws and pull out the blower resistor. Here's a diagram to help you locate it better:



If you have a multimeter you can test the terminal resistances to see if this is actually your problem.

Andrew,

Thanks so much. I just had the same problem with my 2002 Pathfinder a couple days ago. Thanks to your information here I fixed it today for just under $200 and about 20 minutes.

Another strange problem I have is that my car loses oil. It doesn't leak and there is no smoke in the exhaust. I found other sites saying it was a defective right valve cover. Have you heard of that?

Actually, there is another hard problem to diagnose. My dash lights are half out but not all the time. Most of the time my MPH is lit but my Tach is not. Then whenever it feels like it, the whole thing is illuminated. I have no clue where to look for that one.

I appreciate any insight you may have.

Thanks.

Anthony

Thanks for the great help. I picked the part up this afternoon and had it installed in under 5 minutes. You saved me lots of $$$$.

Hi Everyone!

Thanks for all of the help first.

I have a 2001 Pathfinder LE V6 and have had the same problems of my blower not working. Ther was no voltage to the blower motor. So as everyone had done I took out the fan amp and found in my case that the thermal cut off fuse was blown.

For everyone's reference the N-Channel MOSFET was an NEC K2500 9Z

The thermal cut off fuse is a Panasonic N-Series EYP2BN134. I had a lot of trouble finding them so I ordered:

Cantherm SDJ1 DF141S

Digikey Product Number 317-1134-ND

I just ordered this new thermal fuse and have NOT tried it out yet. Since the specs appear to be very similar it should work. I'll report back once I test it out.

By the way when removing the circuit board use a flat screw driver and pry up on the side where you can see the little screw holding the MOSFET down on the heatsink. The side there there is a single brass connector (labeled R1/R2). Then use a small screwdriver and remove that screw. The lift vertically up to disengage the thermal paste which is very thick in consistency.

Hope this help everyone. I'll report back soon.

On the way home last night my A/C started doing crazy stuff. Wouldnt cut off, ran at max speed only. Got online last night and found this post. Picked up the part today and followed the instructions in this thread. Within 10 minutes i had fixed the A/C Problem. This thread is a life saver! thanks a ton andrew. The vehicle is a 2002 qx4 with 116k miles.

Hello all, a new member here, but I'm a bit of bym and have done a lot of electrical work with alarm systems and such, just wanting to get some feedback.

My wife has an 05 pathfinder and the blower is working intermittently. It doesn't run when you first start or drive, but then about 15 minutes into your ride it usually starts working and works fine on all speeds until the vehicle is turned off. It has the digital controls and nav system, but I believe it is a "manual" blower fan system as from what I've read and the diagrams I've seen, I can definately see the resistor module with a 4 wire white clip going to it under the glove box on the passenger side next to the blower motor. However when I test the blower motor, I am getting 12 volts and power to it through the blue wire. Power goes away when I turn the fan off through the controls. So if I am getting power to the blower, then the resistor module should be working, right? Just not sure if I should change the blower motor or module and wanted to get some feedback.Thanks!

Same as the first guy, as in no air coming from the vents, my control panel lights and switches work, you can hear something changing in the engine compartment when I switch speeds, but nothing happens. Where my problem is different though, is my fuses in the dash for the blower motor are blown. Replace them, turn on heater, nothing happens again, but my fuses are still blown...Any ideas?Thanks!

I have

ctenny11 wrote:Changing the blower motor was very easy using the instructions above to remove the glovebox/paneling and took about 30min. I found a motor online at https://www.am-autoparts.com/ for $55.55 free s/h and it arrived in2 days!

I have to same issue ! I have to turn the air/heat on and off a few times before the sound stops. And sometimes it still doesn't stop. Def want to get this fixed before the winter.

I'll order the motor thanks to your post!!

I could find nothing about this in the Armada forum but my 2005 Armada was doing the same thing (blowing full blast or nothing) then a few nights ago we turned it on and smelled like something was burning and now it does not blow at all. Can anyone help with this? Is it the same thing as the fix for the Pathfinder you guys are talking about? Any help is really appreciated! Thanks!

Amateur here - but due to finances, I have to fix this myself.

So, my 2000 Pathfinder's AC/heater faded out to nothing a couple of days ago. History is this:

Bought Pathfinder brand new October 1999. Have taken excellent care of it, doing all maintenance at appropriate times. It hasn't had any significant problems ever over the years and only has around 105,000 miles on it. I still really like my Pathfinder!

About 3 years ago, a heard a very faint rattle by the glove box. I banged it with my fist and never heard it again. One other time, I turned on the AC and it wouldn't turn on. So I just turned the whole system off and then on again and no more problems.

So, I get in the car the other day to go to the airport to leave for the holiday, start the car, and I hear what sounded like sort of a rattle (although not loud). It didn't sound so much like it was from the glove box area. To me, it sounded more like from under the hood. Anyway, I turn the car off and start it again and don't hear it. So I take off for the airport and at first, the AC seems fine. I turn it up a notch to blow harder and it seems to not respond, but it is still blowing. Within about 3 minutes, it goes from blowing to fading away. So it is now not blowing at all.

My friend tested the fuses with a meter (amp meter?> ohm meter? whatever.) and said the fuses are fine. He also said the compressor is engaging, so that isn't it (thank goodness!)

So we figured that the blower motor was the only other choice...... until I found this thread. Now I wonder if it is the fan amp problem.

So, anyone have any thoughts? I have no problem trying to fix this myself. I don't have much mechanic experience, but I have taken on changing alternators, belts, batteries, etc. myself on some of my other cars. So this will just be another learning experience. But I really would like to buy and fix the right part.

So, at the risk of showing my ignorance, what exactly do I need to do to be sure which part is bad -- either the blower motor or the fan amp thing? Thank for any opinions/advice!

*****************************

UPDATE: Got back to airport from my trip and got to the parking garage at the airport and started driving home. Lo and behold - now the fan is blowing again. What the?????? We messed with that thing for a good 45 minutes the other day. We turned the car off and on. We tested fuses. We turned the AC and heater on and off numerous times. Nothing would make it come on. And it had been sitting in my garage all night, as it always does. So now it sits in covered parking for a few days at the airport and I start it and it works?? Can anyone help? Anyone?

Modified by drdj at 3:55 PM 11/26/2009
Modified by drdj at 3:57 PM 11/26/2009

Worked for me.



Friend got me the part for $120incl. tax. Changed it in about 30 mins total (including some time warming up the cabin with a small space heater, lol). Now I have heat again.

Thanks all for the detailed instructions and pictures!!!

I have to say I'm a big "fan" of this forum now.

THANK YOU SO MUCH TO ANDREW224 AND SOLARA!!!

The directions and photos you posted were sooooo helpful and very easy to follow. I was able to replace my blower motor resister all by myself. AND it only cost me $18.00. It was so easy. I have a 1999 Sentra.

To all other ladies You Can Do It Yourself Too!!!

Thank You! Thank You! Thank You!

Jacq

I have to second that. I bought mine from Courtesy parts for $100 for my 2002 PF. Took me less than 5min and worked like a charm! Boy is my wife happy!

Thanks guys!

Not to beat a dead mule in the @ss but my wife's 2002 Pathfinder had the same problem with the blower motor blowing full blast. I replaced it with the module assembly located at http://www.courtesyparts.com/m....html. It worked like a charm. It is now fixed finally. Thanks for the great post. I just wanted to be the 3rd or 4th person to varify that this will probably solve the problem. Sharing is Caring.

mvt wrote:Since I couldn't find a replacement for the original MOSFET, I looked for a replacement. I got a package of ten IRFZ44V via E-Bay (from Hong Kong!) for under $10 including shipping. I replaced the Mosfet in the Fan Amp and nothing happened.

I had the same problem in that that fan was stuck in the high position and would not shut off. I had experience soldering so I bought the MOSFET from Mouser at http://ca.mouser.com/ProductDe...3d%3d

I finished soldering it and reinstalling the fan amp. The problem is partially fixed in that I can now shut off the fan. But I cannot adjust the fan speed. It will adjust on the digital display but does not physically adjust... I do have control of the temp meaning I can go from ac to heat... Could this still be do to the fan amp? Is the fan amp responsible for changing of the fan speed also?

Forgot to mention my vehicle is a 2001 pathfinder
Modified by dred at 1:08 PM 2/18/2010

I had the same issue with blower constantly on high in Dec. I replaced the part per the instructions. Everything worked perfectly for a few months. Now the fan stops running a couple minutes after I turn it down from the highest setting. When I start the vehicle with the fan setting on high, it starts runnign after about 5 or 10 min (usually after a bump in the road or a quick stop). You think the fan motor should be replaced too? I am a chick that really knows nothing about cars, but since I can build computers I figured I could handle this (especially with pictures - that is so awesome). Should I give up and just take it to the dealer so they can rob me blind?

symptoms: blower motor stopped working completely, a/c compressor kicks on when activated, no air blowing through vents

fix: junkyard $20, took old part out, found qx4 in junkyard, pulled part, paid and plugged in new part, worked as good as new!

thanks to my dad lewis for finding this forum, after weeks of debating, testing fuses & blower motor, and some confusion since my blower was NOT working and some folks still have blower only working on high... replacing the module works great.

tip: save some cash by using a junkyard and finding the same part in these vehicles: http://www.courtesyparts.com/m....html * 1996 to 2004 Pathfinder (R50 chassis) * Maxima (A32B Chassis) prod. date: 02/1994-05/1995 Specification:F/SEL *FED.S.SE *CAL.S.SE * Maxima (A32B Chassis) prod. date: 05/1995-02/1996 Specification:F/SEL *FED.S.GXE.MT +*FED.S.SE +*CAL.S.GXE.MT +*CAL.S.SE * Maxima (A32B Chassis) prod. date: 02/1994-02/1996 FED.S.GLE +CAL.S.GLE * 1997-2002 Infiniti QX4
Modified by drewser at 6:36 AM 3/8/2010

I read through these posts, and came to the conclusion that the solutions on this post is exactly what I need to do.I have a 2003 pathfinder se, and a few days ago the heat and a/c stopped working. The electrical system works, meaning the dash shows the auto climate contol working and increasing speed of the fan as the car heats up. Yet, the fan blows hot air, but only at the lowest speed if at all.I just need some reassurance as to the solution for my problem. Im assuming all I need to do is to replace the fan control amp...???

Looks like I had the same problem. I was going to go the MOFSET/Thermal fuse route as I do have some experience soldering, but it looks like the MOFSETs from digikey reference in the post are on back order. I ultimately bought a new amp from Courtesy Parts and it worked like a charm.

My car, a 2002 Pathfinder LE, did have the air filters. I did not buy new ones because I did not want to cut out the slots, but I wish I had as the existing ones were really bad.

Another weird HVAC problem!

I have a '99 QX4 where I had to jump it after leaving the headlights on all night (thanks wife!). Anyhow, after I jumped it, the fan indicator on the climate control panel keeps spinning (like a pinwheel). I can hear the fan cycle between speeds. When I hit the "off" button, it cycles off for a second, then comes back on with the same pinwheel affect.

Seems like I should replace the fan control module thing you guys have been talking about here. Am I on the right track?

I just followed these instructions and fixed the blower on my 2003 QX4. It fixed the issue and saved me a lot of $. Thanks for posting this. It is much appreciated!

Can't thank you enough! Saved me tons, job was done in less time than it took for my wife to return with fast food!

Thanks for the info. here guys.

One small problem. Replaced the AMP and everything spooled up fine. However, when the fan spooled up to high (4 fan blades on the read out), I blew both blower motor fuses under the dash. Could it be that the fan is done as well? No issues at the lower speeds, just on high....

Weird! Any tips?