Quick question about squealing A/C belt
 

Alright, I really suck at tensioning these damn drive belts. If the belt squeals on startup with the A/C turned on or at low RPMs during the first few starts and stops of a trip, does that mean the belt is too tight, or too loose?

The manual specifies a tension for the belt. How and what would I use to measure this with?

well if it squeals at start up its probably to loose.but just hop under the car and feel the tension on the belt from the bottom see how much it moves. it will probably move quite a bit like 1/4-1/2inch now tighten it up so it only moves about 1/8inch and feels tight....

easy comparison for you is if you have a power steering pump as well feel that belt and compare it.

+1; my brief experience with belts (i.e. alternator) is that they have to be really really tight for people like me who do not have the proper tools to make them tight. But as addiction says if it squeals upon startup it is probably on too loose. there is some small little device that supposedly measures the tension but I personally only go by the noise.

ya i just go by feel and noise... if it makes noise then tighten it up more until it doesnt.LOL

With the engine off, you should be able to turn the clutch plate on the compressor easily by hand. If it's binding, the compressor is about to seize up.

Tighten the belt just until it won't squeal, too tight is hard on the bearings in the idller and compressor.

Alright, thanks guys.

Turns out it was both the A/C and alternator belts. Got them both tightened up nicely and no more squealing.

mk378... what if the compressor clutch plate turns easily by hand, but in one small section of the 360º turn it is just a tiny bit more resistant, yet still easy to turn?

That's normal. The scroll compressor has a "once around" action inside.

Alright, thought so. I hear the sound of a gas (r134a) moving when it gets more resistant, so I figure that's how it works. If it was never resistant, then the compressor wouldn't be doing it's job, correct?

Right. It doesn't take much force to turn it slowly by hand, but at speed as the pressure builds up it takes horsepower to keep it going.