Three Way Light Switch Wiring

Typical 3 way switch wiring nm cable in the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box.

Three way light switch wiring.

Connect the wire marked common to the black or dark colored screw. Regardless of what 3 way switch wiring diagram you re following you ll need to use a 3 wire cable to connect the two 3 way light switches. The black line wire connects to the common terminal of the first 3 way switch. Connect the two remaining traveler wires to the two brass or light colored screws.

So what you should see if you have correct 3 wire electrical cable romex is a black power white neutral and now a 3rd red wire. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch. In this diagram the incoming hot wire attaches to the first switch s common dark colored terminal.

When wiring a 3 way switch first screw the terminal screws of the new switch until they are difficult to turn. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together.