Well, I had the mechanic look at it.
No codes were found, so that's ok. His prognosis, is that it's the alternator and that the brushes are most likely not having any tension against the armature. The alternator has 150K miles on it, so I can see where that might be the issue.
When I got to his shop the light had turned off and the gauge was reading fine. The alternator showed it was charging 14.2. But when he got through with his tests, paid and left, the light came back on and the gauge went down. I turned right around and let him check it and the alternator wasn't charging at all. The battery showed 12.6...12.5, etc.
So if I come up with about $381. to replace the alternator, belt (needs changing anyways) and for the 1 hour labor, I can get it fixed.
He stated that if the light started coming on and not going off, to stop driving it. He said the fuel pump would go bad if it didn't have at least 12.6V going to it for operation.
So I need to get it done quick....
He checked the tension on the belt and it was fine. | 
