Thanks guys. That gives me some things to check and I'll go to the forums above.
I was originally going to post this question at
www.allpar.com. Had good luck there before but it was filtered at work. This is one of the few forums I can get to from my job computer. I expect that I can find the answer without even posting the question. Just search the arvhives.
BTW, the truck has 205,000 mostly troublefree miles. No major repairs. Just the typical limited life components every two or three years over the last seven that I've owned it.