Are you running a 3 brush generator? Those are self-regulating, and they run a "cutout relay" (maybe AKA circuit breaker) to disconnect the generator from the battery when the engine stops. What year and type of vehicle are we discussing? Other than on some antique farm tractors, 3 brush generators are totally obsolete, and most of them have been replaced by later type charging systems.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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