Car wiring diagrams: 3 Way Wiring Red Black White, wiring diagram, wire wiring harness, schematic circuit diagram, wiring diagran, wireing diagram, wirring diagram, wiring daigram, wiring diagrams. Then a wire cable going between the two way switches and then a wire cable going from the switches to the load. The wire cable consist of a black wire, a white wire and a bare copper wire, while the wire cable has an added red wire which is hot as well..Feed a length of type NM cable or , if you re connecting to gauge wire between the two boxes. The cable has three insulated conductors white, black and red plus a bare ground wire . Connect the wires to the new three way switches with ground screws using one of the two wiring diagrams Fig..