Wiring question?

[Marine One]

Does your alternator have an excitor wire? This is what "turns on" your alternator and makes it charge. If so, this wire stays hot once the voltage regulator kicks on and tries to back feed your ignition system. You can cut this excitor wire and splice in a diode. The diode will act like a one way check valve preventing the power from ever back feeding again.

Hope this helps.