i put on a new 140 amp alternator and belt last week,now all the sudden the damn thing is squealing like a stuck pig again!! i forgot the belt dressing but hit it with wd40 to no avail. what gives can some one please help??

 

may have some twist in the mounting or a bad tensioner......Had an old truck that took a shot in the front end and the bracket was bent, but didn't know it......Bought an unneeded alternator, and still squealed. Could very well be something else but you can check to see if the mount is twisted with a yard stick.....

 

I had the same problem and it ended up being my ac compressor pulley. Take a look at all your pulleys and make sure the bearings aren't bad in them.

 

Don't use belt dressing unless it's the last resort. Specially on a new belt.

 

Do you have a Goodyear Gatorback belt?

 

a small squirt of water on the inside of the pulley will tell you if it's a bad bearing.. noise goes away then that's it. Since it's water the noise will come back but it's less messy then belt dressing which is pretty much a waste anyway. Find the pulley and replace part.. If it's a new belt then it's likely a pulley which is throwing the belt out of align.. Here's to hoping it's the idler, since that's the easiest to fix.