The alternator belt on my '87 Westy screeches horribly at idle, and
sometimes when you first pull out from a stop. (It stops if you gun the
engine, or while driving at almost any speed.) Replaced the belt and the new
one started doing the same thing after only a few hundred miles. The belt
tension is correct. The mount looks okay and nothing seems visually wrong
with the geometry. The alternator does not seem to be binding. One of the
pulleys had a bit of surface rust but sanding it off made no difference. No
hot spots when viewed with an infrared heat detector. Running out of ideas.
Any thoughts?

Ron Salmon