How to Wire a Three-Way Lighting Circuit
- 1). Run 12-3 non-metallic sheathed cable with ground wire between the two switch boxes and 12-2 non-metallic sheathed cable with ground wire from the power source to one of the switch boxes. Run a second piece of 12-2 cable from the second switch box to the light fixture.
- 2). Connect the red wire in the 12-3 cable to one of the two parallel screws on the three-way switches, and attach the black wires to the other. Connect the black wires from the 12-2 cable to the single screw on the three-way switches. Twist all white wires together and all bare copper wires together with wire nuts.
- 3). At the light fixture, connect the black wire from the 12-2 cable to the black wire on the fixture, connect the two white wires together and the bare wires together. Use wire nuts for the connections.
- 4). Turn off the power, and connect the other piece of 12-2 cable to the power source by twisting black wires together, whites together and bare wires together.
