93 Olds 88-whine when running

I've noticed a whine when the engine runs. A mechanic mentioned it could be the power steering pump. Tonight however I noticed that at idle speed, the dash and headlights would continely brighten and then slightly dim. Is it possible for the alternator to be making the whine? I also searched e-bay for a replacement without luck. Does anyone have the part number and/or know which alternators would interchange? It has the 3.8 V6 engine.

A used alternator is a big risk here get a reman. from a parts hous. Does the noise go away with belt off, checked the tensioner pulley? A salvage yard can tell you which alternators interchange.

Man an alternator costs about $85 and takes about 30 minutes to change out, that's one of the easiest and cheapest repairs you'll ever make, get a refurbished or new one from Autozone, O'Reilly's etc and don't mess around with used junk.