I hear a squealing noise when I turn on my AC. Do I need a new Compressor?

From the information you've supplied it's not possible to determine if your compressor is damaged. Since the vents are blowing out warm air, the system is not circulating the refrigerant. The squealing noise could be coming from the belt on the compressor pulley. When you turn the a/c on the clutch engages. Do you ever hear the noise when you turn on the defrosters? The a/c compressor should run when the defrosters are on. It is possible with a loss of refrigerant that the compressor has siezed due to a lack of lubrication.

Try tightening the belt first or replacing it.

Worse case senario you spend 8$ on a belt and that is not the problem, but the belt will need to be replaced eventually anyways so no harm done.

Best case, it fixes the problem and you dont have to buy a new compressor.

You could also have a leak somewhere causing it to not work.

Make sure the compressor is kicking in, by turning on the car and listening, then turning on the A/C you should be able to hear it kick in.

Personally, I wouldnt put any more money into it if you are about to sell it, if it is the compressor that needs replaced. Let the next owner worry about it. Some people never use A/c even if thye have it.

If the noise goes away when the ac is turned off it is not the belt..it is either the compressor or the compressor clutch(hopefully just the clutch)..

I dont know how hot it is where you are but a very inexpensive fix is to check if that vehicle has an option w/o A/C ..if it is..buy the belt that fits that option and over-ride the AC..When you think about it the car is almost 9 years old..any AC repair is going to be expensive..do you think you will have the car for 5-6 years to appreciate all that money you are spending?

Just giving another angle on this one

I'd definitely try a new belt first..or an adjustment if there is one. . Doesn't hurt to have it anyway. When the compressor clutch is on, there's more drag on the belt which can cause it to slip if it's worn or loose. As it's used, the belt gets warmer and the rubber softens..lessening the squeal.

They also have a spray called belt dressing, that may help. If you're going to sell it, focus on the belt first.

nope there is a belt that runs the a/c,which is dry. Either get it replaced or just grease it up.

serpentine belt.... try making sure you don't start the car with the AC turned on

belt definately a belt

Its the belt dude!!

No, you need a new serpentine belt.

nah, check out your belt, man