Hi all just a question on the 12 volt wire system in our 1972 20' Oday, any idea why there would be three terminal wires at the battery. 1 black to neg terminal 1 red to pos terminal 1 white? to neg terminal The curcuit panel is a upm ultra panel, when conected this way, the buttons with complete circuits, display a red light when not swichted on then red is off when lights are on. Any idea if this is a custom re-wire or did this configuration come from boat yard? Thanks all