3 Way Toggle Switch Wiring. Connect another black wire from the light to the original switch location. Typical 3 way switch wiring nm cable.
Of the three circuit terminals one is called the common and the other two are known as travelers. These are the runners of the circuit. In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box.
The black line wire connects to the common terminal of the first 3 way switch.
The third wire is the common wire that feeds the light fixture and is connected to the black screw on the switch. In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box. Do this before you disconnect any wires from the switches. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together.
