Is it a bearing?
 

Here is the history:

End of last winter, I installed a new tensioner and belt on my car (Stock 2V with Novi 2000). At first, everything was fine. Then, soon after, I was getting some noise. It was manageable at first, and goes away after the car gets warmed-up. Then, over time, it got louder, and the car would need to get hotter before the squeal/chip would go away.

Using belt dressing helps but only very temporarily. Using WD 40....helps, but only temporary. If I spray WD40 directly on the alternator bearing, the chirp goes away, but again, only temporary.

The car is in storage for the winter, but I would like to get it fixed. I just started it and let it run. I really can not tell if it is the alternator pulley, the belt, or some other pully.....perhaps even the new tensioner.

Anyone know how I can isolate the noise? I do not want to start replacing things randomly only to find that I did the wrong thing. I suspect a bearing.....

i had the same problem... i put a big screw driver on the pulleys and listened for grinding. my pulley only chirped on cold start ups and went away when warm. since i couldnt isolate i didnt bother trying to fix and 600-700 miles into a 3K+ mile journey from delaware to california the pulley between the blower and altenator blew up and had me stranded in bristol.

my old roommate had a bad bearing in his alternator and miny didnt sound anything like that. his made this terrible noise all the time the noise didnt go away.

Shit....that sucks. I have been suspecting that same pulley actually too.

Remove the belt and turn each accessory by hand plus move up and down and you will know by how much play each shaft has which one is the culprit.

I had a noise like that, It ended up being my tensioner and pulley assy. dunno about your setup w/ the s/c and all...that tensioner/pulley might have gotten replaced by something else.

The tensioner is brand new.....may still be the dam problem. I used a stethoscope today, and it was not revealing. They all sounded the same to me, certainly none of them appeared to be responsible for the annoying chirp.

My stock ford idler pulley is doing that too, it need to be replaced.