Dilemma:
I have a 2000 Chevy blazer, (4.3l Vortech...4wd 2 dr) that has severe squealing from the belt...
Have had two belts replaced, a new alternator and two tension pulleys replaces...to no avail.
Can anyone help me figure out why the belt squeals, or if it is one of the pulleys...I AM GOING CRAZY WITH THE SOUND...

check to make sure all of the pullies are spinning properly if one of them look to be moving too slow thats your problem. Sometimes if the water pump is going bad it will spin slower or in bursts if the internals are causing unnatural friction. check all of these things out and let me know. Or if you do find the problem post it anyways just so I and everyone else that reads this post will know if we ever come across this problem.

Never thought of the water pump, or the variable speeds of the pulleys. Will check it out and get back to you.
Thanks.

an old trick i learned from a guy to check if the belts is where its coming from is to while the motors running push the stick of chalk onto the belt to cover it and if it goes away then thats ur problem. if not then keep looking.

Just got word from the chevy dealership-turns out that the monkeys at the other dealership applied some sort of resin to the AC pulley which increased its diameter and caused the belt to produce the increasingly loud squeal/ chirp.
Needless to say, the dealership is covering the costs...
I am still curious as to why the resin or belt dressing was applied in the first place???
Will keep you posted on this.