A/C compressor noise

My 2001 SL2 is making a lot of rattling noise. I think I have isolated it to the A/C compressor. I noticed that on the back side of the A/C clutch the plate where the signal wire connects into is very loose when the A/C is not on. The noise seems to be loudest when the A/C is not on. But when I turn on the A/C, that plate tightens up. But the noise continues. Could it just be the A/C clutch or a bearing or something? Or is the noise coming from somewhere not even related to the A/C? The A/C still works really well. I just notice the noise.

The compressor is not likely the source of the rattling. Without knowing anything else, I'd suspect a bad serpentine belt tensioner. They often cause a rattle when they fail on these cars.

Well, Its definitely the ac pulley. Now, my question is, can I just replace the pulley on this thing? or do I have to buy a whole new compressor? The compressor works just fine and I really don't want to have to pay $250 bucks when I can possibly just buy a $20 pulley.

thanks.