I pulled the alternator out and checked the brush length. They were about .1" out of minimum spec. So, I soldered in a new set of brushes, blew out all the carbon powder that had accumulated in the alternator, put it all back together and reinstalled with a new belt. The A/C belt really needed to be replaced so this was a perfect excuse to do that one too. It would appear that everything is working fine. The old belt was a little glazed but not too bad. The truck is running cooler so I would gather that it needed replacing as it was slipping a little on the alternator and the water pump.
Hopefully, it was this simple.
-Beth