FF,
Makes sense. But isn't the start button circuit a relatively low current circuit which controls a starter crank relay (or contactor or solenoid), which in turn magnetically switches the isolated high current circuit to the starter motor?
In other words, isn't the starter button isolated from the high current of the starter motor by the starter crank relay (or contactor or solenoid)? Otherwise, the wires to the starter button would need to be really thick to carry the starting current that long distance?
Also, in a car, there is really just one ACC circuit. But, in a boat, we often have many circuits on a house panel that are really somewhat ACC circuits and aren't on that key switch?
I guess what I'm asking is, wouldn't that diode need to be placed back by the relay (or contactor or solenoid) or the starter vs at the key switch?
Cheers!
-Greg