Black Dust on Alternator Housing?

you know what, I thought about it some more and Brian in post #2 could be right. The way the Mopar Alternator cools itself, I could see brush dust flowing forwards. I don't think it could make it's way through the fan to be "aft of the pulley", but I could be wrong. In any case it's easy to check the brushes. Blow it off and see if it comes back. I would still check the belt etc.