Ok I'm new to this forum and I know the general rule is to search before you ask a question. I have a 95 F150 that had the a/c pulley bypassed. It seems to be seized up. It was like this when I got the truck. The sound really didn't start happening until a couple weeks ago. It's only on start up. I read that the smog pump usually does this and that's where the squeal was coming from. So I went ahead and replaced the pump and now it squeals worse. It eventually goes away after the truck warms up. I also noticed if I get on the gas it will squeal. I've tried the emery pad on the pulleys and cleaned them off with MAF sensor cleaner.

I've noticed I can rotate the belt passed 90 degrees but my tensioner springs back tight. Could all this just because a shorter belt was put on to compensate for the bypassed a/c pulley? Also the serpentine belt appears to be new no glazing no cracks.