I don't know is this will help you out, but when I wired a car I built from scratch I wanted to use just 3 wires with a double-throw toggle switch. I bought a relay box from Ron Francis wiring that worked perfectly. Just a simple toggle switch, center off, with a left and right using just 3 wires. Remembering to turn them off is the only issue, like many other setups such as a motorcycle.

Last edited by 4100 Fire Truck; 02/03/2019 10:41 PM.