Squeaky belt or pulley or something else
Removed A/C belt. Same symptoms.
With the stethoscope I can hear it on the idler pulley AND on the body of the alternator.
The noise is worse with a new belt than with the old belt.
Has a new idler pulley, new tensioner (with a new pulley).
Belt dressing made it so much worse that I spent time with a brush and carb cleaner to remove it from the belt and pulleys.
Removed the accessory belt. No chatter/squeal.
I’m open to any suggestions. I’m out of ideas. Thanks, gentlemen.
Word of caution, spraying wd-40 into the alternator is not the best idea...
So, without a lot of confidence I purchased an AC Delco tensioner pulley and a Continental (formerly Gatorback?) belt.
No squeak.
Ran it for an hour this afternoon enjoying the drive without all that disturbing racket.
Thank you for your time and suggestion, sir.

