battery light

[bidibronco]

In my 94 Bronc' my battery light keeps coming on when the truck is at normal operating temperature and I'm at idle. My volt gauge reads relatively normal (stock gauge for now) and I'm not understanding why my battery light comes on. If I'm driving around 1600 RPM's or so the light flashes on and off and at about 1800 RPM's it goes off? Anyone have any suggestions. I do think however that my bearings in my alternator is going do to the horrible sound that it makes (like bearings that don't want to be turned and they're turning). Any information would be great! Thanks!!!

 

[Roadkill]

If the bearings are going bad or already shot, the alternator needs to be replaced/rebuilt anyway. May as well fix that problem, then see if the light still comes on. My SWAG is that it will go away when you replace the alternator. (Scientific Wild Ass Guess)

Edit:

Defined SWAG