3 Way Switch Wiring Diagram Power Into. On this page are several wiring diagrams that can be used to map 3 way lighting circuits depending on the location. This 3-way light switch wiring diagram shows how to do the light switch wiring and the light when the power is coming to the light fixture.
So what you should see if you have the correct 3-wire electrical cable Romex is a black power white neutral and now a 3rd Red wire. The black and red wires between SW1 and SW2 are connected to the traveler terminals. A variation of the above three-way and 2-Way switch wiring is to bring all of the cables into one wall switch box as depicted in the diagram below and branch off from there to each switch and light fixture.
Replace any regular switches with the 3-way switches.
Power into light switch Box 1 - wire to light from switch box 1 and from switch box 1 to three-way light switch box 2. This is the 3-wire cable that you must have to wire a 3-way light switch. With these diagrams below it will take the guess work out of wiring. All three switches are connected together by a three core and earth control cable.