My car died while I was driving it, but I can put the battery on a charger (or from another car, with jumper cables) and get it running albeit for a short period of time.
I put a multimeter on the batter and I'm getting 12.5v while the car is off or running.
replaced the alternator, still only getting 12.5v.
I'm checking at the posts, at the cables going onto the posts, and even at the alternator (although the alternator shows 0, when off) itself.
I'm stumped!