No, I'm not gaining weight back.  Becky called me this afternoon and said her Explorer was hard to turn, the A/C stopped working, and the battery light was on.  Pretty simple diagnosis; either the car had exploded, or the serpentine belt was slipping or had fallen off.

When I got home, I popped the hood, and, sure enough, the belt was quite loose.  It had slipped off of the belt tensioner.  As I pushed the belt back onto the tensioner, the tensioner pulley broke off into my hand.  The bearing had frozen, and the plastic pulley had melted from the inside out.  Whoa.

I went to the AutoZone and picked up a new tensioner and belt.  They were incredibly busy, but I was happy to be able to get the parts I needed.  Removing the old tensioner proved to be difficult, as the fan blocked all but the tiniest access to the bolt.  After noticing I had better access to both the belt and the tensioner from the bottom, I got it off and the new one on.

I'm really glad the explosion diagnosis was incorrect.