Wiring a 4-Way Switch (DIY)

Oct 15, 2024

A full day

Intermediate

$50-100

Switches are one of the simplest electrical devices. When closed, current passes through it and a light, appliance or device turns on. When you open the switch, current has nowhere to go and the light goes off.

Wiring switches can be confusing, especially with three-way and four-way switches. Three-way switches control light(s) from two locations, like the top and bottom of a stairway. When you add a four-way switch into the circuit, you can control light(s) from three locations, like the entrance to a big family room with three doors from the kitchen, the hall and the back porch.

Here we'll show you how to wire a four-way switch. Four-way switches must be installed into the circuit in between two separate three-way switches. We brought power to the first three-way switch box, which is common, but other configurations exist.

Before starting any electrical project, plan your circuitry and the best route for cables. Type NM cable (nonmettallic sheathed) is expensive, so do some homework and make sure you buy the correct size and quantity of cable. And, most importantly, make sure power is off by testing all circuits with a non-contact voltage tester.

Always consult a licensed electrician if you need help. Safety first; this project is not for a novice DIYer.

Note: this is a complicated wiring setup that requires a solid understanding of basic home electronics.

Bring these cables to your switch boxes and light(s):

Remember, four-way switches only work if they’re installed in the circuit in between two three-way switches. You can have as many intervening four-way switches as you want in the lighting control circuit, but they have to be bookended by two three-way switches.

Always know what you’re working on. Is it a circuit rated at 15 amperes? Is it a 20 amp circuit? The size of the circuit breaker in the electrical panel determines the rating of the branch circuit.

Here we have a branch circuit originating at a 15 amp circuit breaker, with 14 American Wire Gauge (AWG) cable and light switches rated at 15 amps. Whenever you replace existing light switches, make sure the replacement switches have the same rating.

Family Handyman

TMB Studio

Family Handyman

Family Handyman

Family Handyman

Family Handyman