How to Wire a Two-Way Switch

How to Wire a Two-Way Switch


Wiring a two-way switch, also known as a three-way switch, allows you to control a light fixture or other device from two different locations. For example, you may want to turn on a light from the top and bottom of a staircase. Wiring these switches properly is important for safety and functionality. In this guide, I will walk you through the complete process of wiring a two-way switch step-by-step.

Things You'll Need

Before getting started, make sure you have the following materials:

Turn Off Power

Safety should always be the number one priority when working with electrical wiring. Before doing any work, use a voltage tester to confirm the circuit is dead. Turn off the appropriate breaker in the service panel that controls the circuit you are working on.

Identify the Fixture Wires

At the light fixture, you will find the following wires:

Identify each of these wires before proceeding.

Install the First Switch

  1. Mount the first two-way switch in the electrical box. Only remove knockouts where wires will enter.
  2. Connect the line (typically black) wire to the common terminal on the switch.
  3. Connect the neutral (typically white) wire to the neutral terminal on the switch.
  4. Connect the ground wire to the ground terminal on the switch.
  5. Connect a 14/2 wire between the light fixture and the second switch location. Connect to the traveler terminals on the first switch. This wire will carry the switched power to the second switch.

Install the Second Switch

  1. Mount the second two-way switch in the second electrical box near the other location.
  2. Connect one of the traveler wires to the common terminal on the second switch. It does not matter which traveler is used.
  3. Connect the other traveler wire to one of the traveler terminals on the second switch.
  4. Connect a 14/2 wire between the second switch and light fixture.
  5. At the light, connect the line or hot wire to one wire from the second switch.
  6. Connect the other wire from the second switch to the load wire on the light fixture.
  7. Connect all neutral and ground wires properly at the light fixture.

This completes the basic wiring. Turn the power back on and test that the switches work to control the light from both locations.

Three-Way Switch Wiring Diagram

Here is a wiring diagram depicting the wiring installation:

Two-way Switch Wiring Diagram

The line or hot wire brings power into the first switch. From there, the two traveler wires carry power between the two switches in a continuous loop. The second switch sends power via the load wire to the light fixture.

Tips for Wiring Two-Way Switches

Following basic wiring safety and taking care with the traveler wires are the keys to successfully installing and wiring two-way switches. With a little time and patience, you can wire these switches properly. The result is being able to conveniently control lights and devices from multiple locations in a home or building.