I pulled the alternator off. There was a moderate amount of corrosion around the 3 prong electrical connection that plugs in the back. The alternator tested as good at Advanced Auto. I cleaned up the comnnection and re-installed the alternator. Time will tell, but I believe that is/was the problem. During a 2 day period when it was raining the dash warning lights never came on. I suspect the added moisture increased the contact of the corroded attachment.
