2002 GMC Yukon XL AC idler pulley
 

My AC idler pulley started bouncing ALL over the place when the AC clutch is engaged. I mean, really bouncing... to the point that it was making a racket as it hit the built in stops on each end of the idler pulley. So, I figured I would replace it... TWICE!! (thought the replacement was bad). Anyway, that obvoiusly is not the problem. Something in the compressor must be bad. AC was nice and cold till it kicked the belt finally. Any ideas?? I dont have an AC gauge set (unless you count the gauge that comes with the recharge kits...

Thanks,

Rich