Alternator whine?

I have a whine all of a sudden sounds like it’s from alternator but can’t be sure. Do alternatives start to hum or whine when going bad? It’s 13 years old and 272000 kms on it

 

Probably one or more idler pulleys.

 

Yes, Toyota alternators whine when they are going bad. I think it might be a diode. There are youtube videos on it. It's an odd sound, and I looked at all sorts of other components first, but mine ended up being the alternator.

 

I suspected the alternator was going out on mine but it turned out to be the wife. Swapped her for a newer high output model and the problem hasn't reappeared (yet).

Alternators, idler pullies, and power steering pumps all can whine prior to dieing.

 

A couple old fashion trick to isolate sound include a big screwdriver in contact to part and listen like the can and string trick. It works

 

Thanks guys!