Thanks for responding John. I have been giving this more thought. My alternator is less than two years old because I had to have my harmonic balancer replaced. There is the possibility it has given up the ghost, but it's not that old. I'll definitely look into the low idle possibility. I also have been investigating the battery. It was on the car when I bought it. I had to search the web for "high torque" because that's what it says on the battery. The only info I found was that it is made by New Castle and the "high torque" is a marine battery. hmmmmm... possibly a "car" battery would be better suited for my needs? I'll keep on keeping on.
1982 300D (266,001 mi.) looking and running great
1976 450 SLC
1982 Jaguar XJ6 (loved, but gone)