I went and picked up my truck today, since it was in the shop. The battery had been dying overnight because of some drain on it that was always on, even when the engine wasn't running.
It turns out that the rear window was always running, trying to put the window up and that was draining the battery. The comments from the tech on the work order are pretty amusing:
DId you get that?
FOUND REAR DOOR LOCK CYLINDER HAS BEEN REMOVED & HOLE WELDED UP.
I've always complained that the rear window was a pain to use because the only way to lower it was from the driver's seat with the engine on. Apparently, you're supposed to be able to open it from the outside of the vehicle ( which makes sense ) but someone removed it and welded over the hole. Why?
That's what I get for buying a used car, I guess.