Ok, every time the average daily temp drops below about 90, my A/C compressor starts squealing.  I know it's the A/C because hitting the A/C switch and cutting the compressor off and on starts and stops the noise.  I can spray WD-40 or something similar down between the pulley and the compressor body and that will stop the noise for a day or two, but then it comes back.  And it's LOUD.  So loud people come out of their houses to stare as I drive by.

Is there any way I can kill this noise permanently short of not using the A/C or replacing the compressor.  The A/C works fine and I don't use it that much.  I usually leave the top off and drive my other vehicle if it's raining, but I'm currently working on the engine of the Aztek so I've been leaving the top on the Tracker full-time and driving it everywhere.

It sounds like the clutch is going out. It is not a cheap repair, you might be able to find a used compressor for less than it would cost for a new clutch. You will be able to tell if you loosen the belt the clutch will be loose when you wiggle it.

Have you tried replacing the belt and adjusting it properly (a lot cheaper than another compressor)?  If you are spraying wd-40 in that area, then it is possible that some has gotten on the belt and is causing it to slip and squeal.  When belts get old, they will also squeal.  If the belt tightness isn't correct, the belt can squeal then as well.

Ok, I know this is an old thread, but I never did get around to fixing this problem, and now that I changed out all the belts when I was working on my alternator issues, the squeal is MUCH worse.  Can't run the A/C at all without it screaming like a banshee.

The question I have now is could this be the compressor clutch bearing and not the clutch itself?  The bearing I can get for around $18, but the clutch is $113.

First look with the clutch engaged and make sure the belt is not slipping. If it isn't, the thing to do would be to take the belt off of it and examine the clutch and bearings If it is loose you should be able to tell what is wrong.

Belt was the first thing I checked.  It's definitely not slipping.  I'm going to pull the belt off again this weekend and take a look at the clutch and see what I can see.

Another thing to check for is any "wiggle" in the compressor caused by a loose or missing mounting bolt or a broken mount.

Recent queeling on my GM alternator was caused by a broken mount.

That said, My bet is also on the AC pump's clutch or clutch bearings.

Time to check out the Pick-N-Pulls  (or give Hawks Strictly Suzuki a call) for a replacement AC compressor.

Well, this is getting stranger all the time.  Turns out the squeal is NOT the compressor at all.  It's my alternator.  But here's the weirdness:  If the AC is on and I start the vehicle up it will scream like a banshee the whole time the vehicle is running.  Turning the AC off and on just stops and starts the squealing.  However, if I leave the A/C off, start the tracker up then rev it to about 2000 RPM's before switching the AC on, it won't squeal at all.  Stays perfectly quiet for the entire drive.

I just put a new alternator and belts on, and it was doing virtually the exact same thing with the old alternator, belts, etc.  The belt doesn't appear to be slipping, as far as I can tell.  Is there possibly any way to use a timing light or strobe to watch for belt slip?

EDIT:  Problem Solved.  Had a friend come over and put a pry bar to the alternator while I tightened the adjuster bolt....  Not sure if the bolt was already stripped out or if it happened while I was tightening it back up, but it was definitely stripped.  Put in a longer bolt that goes all the way through and put a nut and lock washer on the end, tightened it up again while he was prying on the alternator and we apparently exorcised the banshee.