self tensioner. pull up hard on the belt and see which one moves. you will need a long wrench to release the tension to remove the belt. i would replace the tensioner as well. they are common failures.

Roy

Answered by ASEMaster6371 (expert)
24,973 answers provided

Thanks Roy, but the belt is already off, I need to put it back on and eventually replace it. Neither of the pully's move, so that's why I didn't know which it was. Will try again.

Response from pahgolf
1 question asked

the one pulley should have a big spring on the back of it.

roy

Answered by ASEMaster6371 (expert)
24,973 answers provided

Thanks Roy, I figured it out from what you said and another look at what I was dealing with. Was able to get the belt back on and tension appears to be adjusting fine. Restarted the truck but now it's squealing really bad and appears to be smoking, but all pullys are spinning. didn't leave it running. Will have to check tomorrow in daylight.

Response from pahgolf
1 question asked

Remove belt spin all pullies by hand to see which one in draging. Also make shore the a\c clutch is not locked up.

Answered by djcl (expert)
788 answers provided

Will do. Before the belt slipped off it was a rattle/vibration noise and seemed like the alternator but I checked that, the idler, fan and tension all seemed to rotate without hesitation or sticking. Will pull the belt and test them all, along with getting a new belt, will see what happens. Thanks again. pah

Response from pahgolf
1 question asked

Let me know it works out

Answered by djcl (expert)
788 answers provided