Need a plan troubleshooting engine, overcharge surges?

[hanleyclifford]

If you see this, you might want to know...
I never found a wiring problem, although I jiggled and wiggled (the wires, that is...) The batteries tested just short of "bad" and the alternator tested "bad". New alternator, which has the more modern regulator on it, and since I had 'em out and they are old, new batteries. All seems good now, real good; engine ran smooth and strong during the cruising season.

Glad to hear that you're running well again, but at the cost of new batteries and alternator. I'm not convinced, however, that you have solved the "problem". Selection of sensing location has a lot to do with battery health and voltages can vary all over the system, especially where combiners are involved.