NOT a dumb question. The answer is NO, I have not had any time to really get down on it yet. I am confident (not to be confused with sure) that it was charging when the BATT light was out with engine running.
Kinda hoping one of my MR50 brothers would chime in with "Oh yeah, that's real common with these trucks, here's how to fix it forever", or something like that. No such luck so far.