Just recently I was driving on the highway and chucked my tensioner pully (siezed bearing), no big deal. After fixing this, I've noticed that the volt meter seems to be bouncing a bit on it. The truck is a '95 w/ a 351 and 372000km (232000 mi). I've changed the alternator a couple years back too. It's at the low end of the meter at an idle and then up to normal when under load. Any thing?

 

Sounds like the belt may be slipping over the alternator. Is it a new belt and new tensioner or did you just change the one pulley?

 

[QUOTE=Rusty but trusty;3025768]Sounds like the belt may be slipping over the alternator. Is it a new belt and new tensioner or did you just change the one pulley?[/QUOTE I only replaced the pulley, as the belt looked in pretty good condition. That dose make sense however. Thanks.