We have always used a cogged belt on the alternator. We're thinking about getting an old-style V belt to see if that makes any difference.
We've tried adjusting the belt every which way.
Too tight.
Too loose.
Just right.
The only way to lose the squeal is to use the 1/2" belt. But then the alternator doesn't charge.
We get 14.1 volts with the 5/8" belt.
We get 12.2 volts with the 1/2" belt.
We get 11.7 volts with the 1/2" belt and the headlights on and the a/c on.
So I wonder if this could be the problem.
There is a huge difference between the size of the "valley" for the crankcase pulley and the alternator pulley. (I just jammed plumber's putty into the pulley to get these casts.)
But I have no idea which pulley to change, or what size I would need. I don't even know how to measure a pulley. Or if this would make a difference anyway. Aren't they all the same? A pulley is just a pulley, I would think.
And I don't want to just replace parts willy-nilly. Although I probably will end up doing that.