My 99 Grand Caravan started this noise whenever I turn on the A/C. It almost sounds like a drag on the engine. The A/C cools fine but this squeal/whine starts up whenever the A/C is engaged. I added freon to see if that was the problem. It made it good and cold but did not change the sound. Could this be the compressor clutch? Any suggestions on what I should look at first or how to repair? Any advice is appreciated.

 

Sound like your clutch. Squeal Noise could be a bad belt or needs tightening

 

if u have a 3.0 engine then u can tighten is u have a 3.3 or 3.8 then no adj needed bad compressor,belt or tensioner

 

I had what sounds like a simular issue with my 96 Ford Explorer about 3 years ago. I was able to look at the compressor and see that the clutch was locking up and sticking... I could even see a little spark every now and then. I shot it with a little WD40 (I love that stuff) and for 3 yrs now it's been working fine. Just wanted to put this out there for you or anyone else that may have a simular problem.