He insists that he's checked all the wires for a good connection, but I'll let him know about the hidden grounds you mentioned. Later this morning, he's replacing the alternator, so we'll see what that does.

It's frustrating that I'm not there to help him troubleshoot this problem.

Will report back...

If you go to the Zoo, always take something to feed the animals - even if the signs say "Do Not Feed The Animals". It wasn't the animals that put up those signs!