I replaced my alternator yesterday and when I started it up the belt squealed. When I drove it the squeal started when I pushed on the accelerator and would disappear at around 3500 rpm. Is the belt bad, to tight, or to loose?
Be careful not to over tighten... You'll wreck your alternator bearing...
Check tension with a cold belt.
An easy way to get a good estimate of proper belt tension is to reach in and twist it.
If you can turn it upside down it's too loose.
If you can't turn it half that far then it's too tight.
