1971 Plymouth roadrunner, 383 engine. Newer stock style alternator bought and has been sitting for 18-24 months while I have been getting it up and running again.

Long story short, I got the engine started yesterday.

The alternator spins free by hand with no belt tension. The belt tightened and it is locked solid.

Started the car and the belt was spinning but alternator would not turn. It squealed and smoked the belt.

Took off the very hot belt and the alternator spun with no problems by hand again. Water pump pulley is also free and spins effortlessly.

I have another alternator in my stash, but I was wondering if anyone has ever seen anything like this before. It's a first for me.

Thanks
eightlitermopar