Why does the dash gauge switch from battery to alternator?
Why does the dash gauge switch from battery to alternator? OK now that is starting to make sense. If the dash gauge switches over from reading battery voltage to alternator voltage after the engine starts, and there's a diode between the alt. output and the battery, it would explain a lot. I will take readings at the alternator and let you know what I find. Why is the voltage reading on my alternator going up? While watching the voltmeter display, start wiggling wires at the back of the alternator, the battery, and the remote voltage regulator (if there is one)....