Belt Tensioner Issues

I have a 1993 Olds 98 Touring Sedan, and the belt tensioner that adds tension to the supercharger belt seems to make a loud rattling noise. It's constantly fluctuating, although as soon as the A/C compressor kicks on, the noise goes away. Has anybody experienced this, or does anybody know where I can get a belt tensioner (if that is what the problem is). Any help will be greatly appreciated!!

Sounds like the tensioner is a bit loose since your problem goes away after the AC kicks in, putting more strain on the engine (and therefore the belt). I dont think you need a new one since there is a way to tighten/adjust them. I haven't ever tightened one myself, but I'm sure if you got a Chiltons or a Haynes manual you could find out.