I have a service manual and I've gone through the self diagnostic program which shows the sensors to be ok. I know I have to go through and start checking connections as the manual instructs.

I have checked the two fuses and the relay on the left side of the dash which are all fine.

I'm thinking the next thing to check is the fan control amplifier.

My question is... Has anyone else here experienced this problem and what did it turn out to be? Are there any common problems maybe I should check first before I go tearing up the dash?

Thanks,

Andrew

Modified by Andrew224 at 8:40 PM 10/31/2007

It is the only malfunction/repair I've made to our Pathy since it was new. The fan amp seems to be a weak link (a very common issue) since it is a small computer board that heats up and although it has a built-in "radiator", it just gets too hot and fails. Luckily, an easy fix and an easy DIY (though not cheap).

Typically, when the fan amp fails, it loses it's ability to act as a rheostat (on auto. climate control models) and reverts to high speed only. That's how mine acted up... no variation in speed... just on full blast with no way to shut it off.

While what you describe is somewhat different, I'll bet it's a malfuntion of the fan amp control board. Just replace the part.

Good Luck!

Thanks for the input.

Andrew

Step 1: Open the glove box and use a common screwdriver to gently pry the plastic retainer with the cord off the right side of the glove box (while it's open). It should come off without much of a hassle.

Step 2: There are two plastic pins, one on each side on the bottom of the glove box. They have a part that sticks out and should be easy to find. Just push them towards each other, one at a time. Once out, the glove box will come out.

Step 3: Unscrew the two phillips screws that hold the wood trim piece (on a QX4) on and then gently work it free by pulling it up and out.

Step 4: Remove the other phillips screws around the panel (I think there are about 7 more) and the plastic panel should come out. Watch for a wire that goes to the glove box light, it needs to be disconnected with a simple turn before the panel is completely free.

Step 5: Insert the common screwdriver into the left side of the wiring harness that goes into the amplifier and gently pry it and pull it out. (The fan control amp. is white plastic, about 2 1/2" tall, with a phillips screw on the top and bottom with a wiring harness that goes into it).

Step 6: Unscrew the two phillips screws from the fan control amp. and it should come right out.

Go in the reverse order to put back together.

It'd be a good idea to replace the in cabin air filter (2 piece filter) when you do this as it'll be right there. Just pop the metal clip off the bottom filter, remove the bottom filter, let the top filter come down and then remove it. Replace in the opposite order.

You can get the in cabin filter (Nissan part #27275-2W625) from your local dealer or order it through one of the sponsers of the site. It should be about $20. I've ordered parts from Riverside (CA) Infiniti through Jason (he's a member of the forum too) and have been happy with the prices.
You can e-mail him at slapinfunk@gmail.com

Andrew

If you have any questions or run into any problems, feel free to e-mail me at aarmit1@yahoo.com and I'll get back to you ASAP.

Andrew

Andrew224; your instructions were perfect !! I saved Mom a whole lot of money for a 15 minute fix. Granted I took some risk in just going right to the amplifier, but luck paid off.
-Ken

Andrew

I had this problem with my '01 Pathfinder, and had a mechanic look at it and he could not find the problem. I came across your post and instructions----found a genuine Nissan discount parts site, and ordered the part for $107.00 (inclucing shipping).
The part arrived 30 minutes ago, and it is installed and my a/c and blower motor are once again working. You probably saved me a good $500.00.

Many, Many thanks Andrew. A 10 year old could have put it in too!!!
Bill

Thanks for your help with this problem. You saved me lots of money!!

The in-cabin filter traps quite a bit of dirt and debris and shouldn't be overlooked as optional as far as changing. It should be changed once a year or every 12k miles. It seems that the lack of changing the in-cabin air filter may lead to reduced air flow over the fan control amp. Which in turn could possibly lead to overheating and failure of this part.

I'm sure a lot has to do with the dealers charging over $100 to change this filter which is a tall order to do every year. But after you see that you can do it yourself for about $25, it tends to get changed more often. I know it has in my case!

Andrew

It doesn't sound necessary, but I don't want to do anything stupid. Thanks again.

Andrew

Replacement took 20 minutes and everything is working great. Amp was $133 out the door and you saved me at least $100.

Thanks again.

Andrew

Also, where do you guys get your part from the dealer near me wants $150 for the amp. I managed to find it on courtesyparts.com for $110, just wondering if anyone has ordered from that site before? Here is the link to the part I am going to order if someone could let me know that it is the right part.

http://http://www.courtesypart...t_Cod e=27761-70T03

Thanks,

Rob Pivo

Modified by PivoArch at 8:14 AM 3/6/2008

The in-cabin air filters that I use are in Nissan Filter Kit 27275-2W625.

There should be nothing that needs to be cut. The filters are just to the left of that amp. you replaced. There is a small metal clip that needs to be popped off with a common screwdriver and the filters will slide out one at a time. They are stacked on top of each other. You can see the grey plastic edge of the filter next to the area where you were just looking. The filters may even have a part number printed along the edge. The filters fit in so that the air passes through them left to right and you will be looking at the skinny, hard plastic edge.

Let me know if you get it. If not, I can take a picture and send it to you. If that dash panel behing the glove box is out of the way as it would have to be to change the amp. It should take you no more than 15 seconds to switch out these filters. You should use no other tool other than a common screwdriver to do some gentle prying to get the clip off.

I hope this helps.

Andrew

As far as where it's located, I really couldn't tell you. When I started poking around, I got a service manual and it walked me through it. I would suggest the same. If your mechanically inclined, it couldn't hurt to take a look yourself. Most likely it's behind the glovebox and it'll have a wiring harness going into it and it'll probably be screwed in with a couple screws. The part has a plastic top where the wiring harness goes into it but the rest of it is metal and is kinda long and vented to dissapate heat (as this part heats up frequently and leads to it eventually failing).

But like I said, I'm just an amature who figured it out on my own with the help of a service manual and the input of some other people here on this board.

Good luck.

Andrew

I would think it is the same part, it's basically the same truck. I suggest that you call your local Nissan Dealership's Service Dept and verify as this part seems to be a non-returnable part (so don't get the wrong one!).

Quote, originally posted by InfinQX4 »

Can the in cabin air filter be replaced without taking out the blower (2000 QX4)? I know it's not a big deal to pull the blower as I have replaced it already, but didn't think to check the filter while I was in there. Spaced out I guess...

I can only speak for '01s and newer as that is the model that I have. I've never worked on a '00.

Anyone here with a 2000 or older QX care to chime in?

Quote, originally posted by PivoArch »

Ok, so I go the Module Amp in and that fixed the fan problem, however the Nissan dealers near me gave me in-cabin filters with the part number 099M1-VP003. The instructions that come with those filters say to cut the black box that would contain the filters in order to replace the ones that are in there. (Is that common?) When I cut open the box there were no filters in it, so I was just curious if I am in the right place or am I completely off base trying to replace the in-cabin filters?

After looking into this, I think these directions are for models that were not originally equiped with an in-cabin air filter. You actually cut out a hole to put the filters in.

Andrew

Paul

OK...my case is exactly like Andrew224. 50,000 miles 2002 QX4's fan blower decided not to work 1 day. (wife's car). I have test the AC button and did hear it "clicks" on and off. I have try to turn on full blast on the fan but nothing happen. So that fits perfectly like what Andrew mentioned above, I have to replace the Fan Control AMP. I am sure if your fan is blowing full blast without slowing down or adjustment, the same problem occur.

Parts....ordered (by phone) @ Courtesy Parts....just like Andrew and other mentioned...probably the cheapest area for genuien Nissan parts. I've talked to JOE there and ordered part # 27761-70T03 (Module Assy-Pow) . Also, I might as well change the in-cabin filter, however, the parts number listed above does not match what Joe had found. He said, this is a direct fit to QX4 and Pathy and the filter parts # is 999m1-VP003.

Total amount, shipped to Chicago area, within 2 days....$158 something.

Courtesy Nissan - http://www.courtesyparts.com/

You should CALL instead of order online, cause I can't find the filter online and I prefer to talk to real person to confirm my order instead of a computer.

OK...got the parts within 2 days...but I think anyone before ordering the parts, please follow my steps and see you are capable to do all these installation/removal by yourself. Not everyone is very car/machine friendly, so you might need to ask someone that know what he is doing or....saving money is not your option, you have to let the dealer to make your hard earning money. But honestly, I think this is a stage 3 (out of 10) DIY fix that even a 10 years old can do (like someone mentioned above...) So...follow these steps and see you can get to the stage that you can find the Fan Control AMP and remove it. If you can remove that AMP, then you can go order the parts and install it yourself.

Yes...your car can still run without the amp, just don't turn on your climate control and HOPE it is not 20 degree outside (you don't need AC, but you do need HEAT...)

Ok...here are the parts and how they look (and their parts number on box)

OK....step 1, open glove box, remove the stringer on side, simple step

Step 2...Flip down the 2 lower plastic pins, then yank them toward center. Pull harder and both pins should be out completely.

Step 3....remove 2 screws and get that plastic wood panel out of the way.

Step 4...remove all 7 screws.

Step 5...remove 2 more side screws

Step 6....if 1st time removing this panel, need to use some force to swing it out...don't be afraid, it is not that hard to pull it out.

Step 7....panel should be down.

Step 8....remove glove box light fixture, snap and pull, may be check the bulb as well, mine blew long time ago and it is the perfect time to replace that.

Step 9...you should see the whole picture, the FAN AMP and the In Cabine Filter...item # 1, 2 and 3.

Step 10...unplug fan amp wire plug

Step 11...remove 2 screws. The AMP should be about to slide out without any trouble. If you have the new AMP parts, replace it in reverse order.

Step 12....if you have the new AMP in...it is a good idea to start your car and try out the climate control system JUST to make sure the AMP does take care of your problem (mine does...awesome)

Step 13....remove filter clip at the bottom. Slide the lower panel 1st, then the upper panel.

Step 14....use the already came with clip (with the new filter), plug in new filers, clip in new clip....

Step 15....if you want, you can fill out the "Date tag" and the filter notes and stick them onto the panel like mine. It is totally optional, not required but it is there, might as well do it...

Ths is it...follow all the steps in reverse order and you are done. This site and Andrew224 (and others) just saved me $700 because the local dealer said they have to do all the testing, this and that....total was $900 plus TAX and I have to leave the car for 2 days there and they don't have any opening untill early MAY...

Good to save money...and better, good to share with others and help others to save more money...

The filters I got didn't come with stickers or a new clip. Maybe that's why the numbers were different? You're right, it's best to call to speak with a live person to ensure you get the right parts.

Happy motoring!

Andrew

The Pathy does not come standard with cabin filters. If you want to install them, then yes, you do have to cut/remove the plastic knockouts where the filters go. I had to do that on my 02 Pathfinder. The knockouts are there to prevent air leaks when there are no filters installed. The filters I bought by the way, came with clips.

Thanks for confirming that for me I was begining to think that I had cut something I wasn't supposed to.

I think I have the same problem with the Fan Amp. I have taken everything apart. I get voltage at the fan amp, not at the fan motor. I've checked the fuse and the relay, they are fine. Looks like I'll but the replacement fan amp tomorrow.

thanks,
Brian

Anyhow the filters i picked up are not OEM so i dont have the "cut the box" instructions. can you post up that part of the instructions??- this isnt some thing i want to mess up on.

thanks!


Modified by GTIRNN14 at 9:25 AM 6/6/2008

http://www.courtesyparts.com/i....html

thanks