2002 pathfinder ac problem

[Gatorash]

So, about a month ago the ac in my pathfinder started running on high continuously. I could still control the temp but no matter on or off it ran full blast. I had it looked at at a shop and they said I needed a blower motor resistor and a fan control amplifier. In the meantime, it stopped all together. When turned on you can hear something trying to work but nothing. After finding this forum I learned that it's a blower motor resistor and its a common problem and an easy self fix. So I ordered the parts, and cabin air filter for good measure thinking I'd save myself about $800 (they wanted over $900 to fix it). Well I got the parts in it today, and the air is still not working. Any ideas what the problem could be? Thanks in advance!

[4xq]

Did you check fuses for the blower motor and a/c? Sometimes when a high current part like that fails it takes out fuses.

[Gatorash]

I have not. Where would I find those and how do I know if they are bad? And where do I find replacements and is it a hard fix? I'm kinda new to attempting to fix things myself so I'm sorry if this is a stupid question.

[Gatorash]

Update: we didnt drive it it yesterday after replacing the resistor. This morning when taking kids to school as long as I wasn't idling I was getting a very weak blow of cold air. Fuses? Blower? I don't know but I hate to take it somewhere. I just got it out for replacing spark plugs and a coil.

Also, the death wobble- it's like fish tailing that just becomes stronger and kind of takes over the whole vehicle right? I've got a wobble but everyone that has looked at it doesn't think anything is wrong since the front suspension is fine. I don't think they've looked at the rear- that would be control arms/bushings right? I wish I had the tools to fix it myself since I'm having the hardest time getting anyone to listen to me and look at it or fix it. Shop a said no problem in rear as its a solid bar and front is fine. Shop b said front is fine. No one has looked at the rear.

[atraudes]

Shop A is quite wrong. There are four rear arms (links) that connect the rear axle to the body, and each of them has a bushing at each end. If you're feeling the back moving around like it's fishtailing when turning or at higher speeds, that is indeed the infamous "death wobble". Check out this thread for the full details, what your options are, and how to fix it. If you're not up for taking it on yourself, maybe read through it and print out some pictures from the FSM so that when you go back to a shop you know exactly what you're talking about and can show them where to look. I highly recommend getting polyurethane bushings instead of the plain Jane rubber as the rubber has been known to wear out in a matter of months Good luck!

[Gatorash]

Is there a link to the FSM and what is an FSM? Sorry I'm a noob

Also difficulty level of fuses or the blower replacement? Any thoughts or ideas on what is still up with my ac would be appreciated. It's getting hot in alabama!

[atraudes]

Sorry, I'm so used to throwing around acronyms FSM = Factory Service Manual. It's the Nissan-supplied repair and service manual for our vehicles. You can find all of the sections for yours here. To get info on the rear control arms, check out the Suspension section, specifically the components section under Rear Suspension on page 18. The parts you care about are the upper and lower links.

Sorry, no tips on the A/C. I'll do some looking around later and see if I can find anything. In the meantime, have a look through the heating and air conditioning section of the FSM and see if anything catches your eye (you can use the index (IDX) to figure out which section you're looking for in the future).

[4xq]

Ok, if I understand correctly after you replaced your fan control amplifier, your fan began working correctly - the fan works correctly on the different low, medium, high settings.

Now the problem is your A/C works, but just barely, because the air is only a little cool, not cold. That is a different problem than your fan problem.

The most likely cause of your problem with the A/C is a low freon charge. Low freon can be caused by a slow leak, or a larger leak which loses freon more quickly. Also, it is common to lose freon very slowly over the years as the car gets older. I have an 02 Qx4 which needed freon last year. No real leak which required a shop repair - I just needed to recharge the freon.

A slow leak does not necessarily need to be fixed right away. You can add freon to the system when it is low. However, you can add too much, and that also can cause problems.

You can purchase a 12 oz. can of freon at the parts store and add it yourself if you wish. You must add it to the low pressure port. Never add freon to the high pressure port. If you are unfamiliar with all this, you can ask a couple of shops how much they would charge you to just add freon. They have pressure gauges they attach to the low and high pressure ports so they add just the right amount.

Nice job fixing the fan amplifier - sounds like you saved quite a bit of $$. FSM is the factory service manual for your vehicle. All the sections can be downloaded here:
http://www.nicoclub.com/FSM/Pathfinder/2002_Pathfinder/

[Gatorash]

I wish it was working! About a month ago it only blew on high constantly, no matter the setting (if I switched it to manual). Then a couple weeks ago it stopped, except first thing in the morning, once again only on full blast, but I could still control the temp. I thought it was the resistor so I replaced it yesterday, after about a week of absolutely nothing. I could turn it on or off, and you could hear something trying to work, but no air. This morning I had very little, but nice and cold air coming out, now it only works on Econ, once again very little.

[atraudes]

Waait a tick. Can you take a picture of the resistor you replaced? When this sort of problem occurs with auto climate controls, the problem component is the fan control amp, not a resistor. This post will describe it, how to get to it, and how much they run for (up to $200 new, apparently).

Is that the same thing you replaced?

[Gatorash]

The part I replaced was the same location as that post describes and what I took out was the same (or looked to be) as what I put in- part 27761-70T03. Ran me 115ish. I replaced the cabin air filters at the same time.

[4xq]

Nope, guess I really did not understand correctly.

Atraudes did a good link there.

You may have tried this but:
1. Turn AUTO off on the control panel.
2. Turn MANUAL on. Manual should be showing on your display, "auto" should not be. The A/C is now off.
3. Using the fan control, cycle the fan from low up through high.

Does it work correctly?

[atraudes]

Apparently I typed this out and didn't submit...

Cool beans. Check out this post. Check the fuse again for good measure. I saw a couple of accounts throughout the thread of people replacing the fan control amp and it not working in the same fashion as you, but they were able to get it working with the above-linked fix (or some variation of).

[Gatorash]

I tried the turn off and cycle through today- not really any change except if I was getting nothing I started getting a little bit.

Where do I check the fuses at? I'll try that then if still no go try the other.

[4xq]

Sorry, haven't been able to get on here and post. Did you find your fuses?
They are underneath the dash next to the driver side door.

[Gatorash]

Sorry- I've been out of town at a funeral and took the other car- this morning everything worked perfectly when I first started the car (mid 50s temp). It works Devils I was idling, blew cold or hot, all speeds, all vents on auto or manual. Then I turned it off and back to it sounds like it's clicking but hardly anything coming out of the vents but it is cold to hot as I set it, just hardly anything blowing- it does blow faster/harder the faster I go but it slows to nothing when I'm stopped. Guess I'll check out fuses asap unless someone else has another idea.

[Gatorash]

I found the fuse box, and I think according to the map there are 3 fuses it could be. I pulled them all and they seem to be ok- they look closed. However, they look super old, like the bends that go in the box look corroded/old.

[4xq]

Okay, your blower motor is fixed because , as you say, " it does blow faster/harder the faster I go".

What you mean is the cold air stops blowing at idle correct? That means you need freon in the air conditioning system. I'm going to suggest you take it to a shop and have them recharge the freon. I think it will be ok then.

You do not need the full a/c service I don't think, just need to add freon, which will cost quite a bit less.

[Gatorash]

I suck at explaining things I think

First, back in late February or early March it started blowing full power regardless of the speed set. If you turned it off it blew through the floor full power.

Second, in March maybe? It quit all together and you could turn it on or off and it made noise like it was trying to work but nothing through the vents.

Then, I replaced that part and when I'm going over 25 or so I get cold, but very weak pressure air blowing. I can change the temps but it doesn't blow enough to cool the vehicle. The faster I go the harder it blows but still not anything enough to keep the kids in the back cool. When idling I get nothing at all.

Yesterday morning, when it was relatively cool outside (low 50s) it worked perfectly- blew cold air or hot air both in manual and auto every speed and every vent. It was working. Then I turned it off to see if it would still work (never turned the car off, this was during school drop off) and back to what it was since replacing that part.

Found the interior fuses today and pulled the ones i thought it could be according to the map. They looked fine through the window but the prong type things you put in look rusted/corroded.

Right now, when I turn on the air on manual I can hear something come on and it sounds all weak/sick and if idling I get nothing but it will cool or whatever I set the temp as if I'm moving, but not enough to cool the vehicle or really even keep me cool. It's not even blowing hot air. Auto gets nothing period no matter what.

I hope this makes more sense. Sorry, I'm a girl, and new to this whole diy thing with my car.

[Gatorash]

Could the new part have just been bad already?

[Gatorash]

Just replaced fuses for good measure- no change. Is it just coming through the vents when on manual because its on? I can control temp but no matter what speed I put it on I get minimal (pretend someone was blowing on you) air out of the vents. Nothing when it's in auto.

[atraudes]

From what you've described, it sounds like when it's not operating properly, the fan's running at a really low speed which is just enough for that breath of air you describe. The increased airflow you feel when traveling at higher speeds is simply because the air is forced in through the fresh air vent due to the increased outside air pressure. Unless you have it set to recirculate inside air, a flap will open to allow air in from that vent outside right below the windshield.

Did you have any luck inspecting/replacing the MOSFET as suggested in that last link I posted?

[Gatorash]

Not yet. That I will have to have help with as I don't know how to solder. So, basically, the new part was a bum part then right? Should I just send it back for a replacement?