Loud rattle/grind, Alternator?

2005 Tacoma 4.0, unmodified
I was convinced my AC compressor was shot, having been useless for the last 6 years. Never needed it once here in Kodiak, Alaska. I bypassed it with the shorter belt method, worked fine, but the grind is still there.
Could the sound be the alternator? It’s charging fine but maybe the bearings are toast? It felt fine when I spun the pulley.
It’s a loud constant grinding, sounds like sloppy bearings. Increases with rpm’s.
Thanks for any suggestions!


https://youtu.be/CcLravog96k

 

Take your belt off and give your idler pulleys a spin/wiggle. They should not 'free wheel' when spun. If they do, I'd recommend you replace those first.

 

I think I’ll try the idlers next, it’s cheap.
**Bonus: I now experience a noticeable increase in power now that the AC compressor is deleted.