Connect the two remaining traveler wires to the two brass or light colored screws.
Three way light switch wiring.
Connect the wire marked common to the black or dark colored screw.
This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch.
Installing the switches and light 1 attach the black power cable from the wall to the general screw black in the three way light switch.
The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch.
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.
Connect the ground wire to the green screw.
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.
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.
In this diagram the incoming hot wire attaches to the first switch s common dark colored terminal.
The black line wire connects to the common terminal of the first 3 way switch.