[Glenn and Laureen]

Genman wins by getting closest to the actual problem. A mechanic confirmed for me that the starter is not disengaging until I turn the ignition switch to off. The root cause is that the ignition switch circuit continues to send power to the starter after the key is released. Does not stop sending until the switch is moved to the off position.

So, good news for me. No alternator or starter problem and no engine problem. Do need to replace the ignition switch and a really old relay in the back electrical panel that serves the starter.

Thanks to everyone for your advice. Laureen and I learned a lot and also met a good guy who is a diesel mechanic and all around Mr Fix It for future reference.