Interactive diagram + guide

4-way switch wiring diagram

A 4-way switch sits between two 3-way switches so you can control a light from three or more places. Flip any switch on the diagram to watch the travelers swap.

Tool
Interactive 4-way switch wiring diagramThree steps: pick your setup, flip the switches, wire it

Step 1 of 3

Which setup do you have?

Look in the box with the breaker off: what matters is where the power cable comes in. Pick the one that matches, or keep the one already selected.

Step 2 of 3

Flip the switches

Tap a switch, button or GFCI on the diagram. Glowing wires are carrying power right now. On a small screen, scroll the diagram sideways.

4-Way Switch Wiring With Power at the First Switch wiring diagramPower inSwitch box 1Middle switch boxSwitch box 3Light box14/2 cable14/2 cable14/3 cable14/3 cablebare copperwhiteblackbare copperwhiteblackbare copperwhiteredblackbare copperwhiteredblackbare copperbare copperbare copperFrom breakerHOThotNEUneutralGNDground3-way switch 1upCOMCOMMON screw (the dark/black one)Ttraveler screw (brass)Tother traveler screw (brass)GNDgreen ground screw4-way switchstraightINfirst pair screw (usually brass)INfirst pair, other screwOUTsecond pair screw (usually dark)OUTsecond pair, other screwGNDgreen ground screw3-way switch 2upCOMCOMMON screw (the dark/black one)Ttraveler screw (brass)Tother traveler screw (brass)GNDgreen ground screwLight fixtureONBLKblack leadWHTwhite leadGNDground lead or screwwire nut: neutral splicewire nut: ground splicewire nut: neutral splicewire nut: ground splicewire nut: neutral splicewire nut: ground splice
  • Black: hot
  • White: neutral
  • Red: hot / traveler
  • White + black tape: hot
  • Bare copper: ground
  • Wire nut
  • Glow: carrying power now
Travelers from one 3-way land on one same-colored pair of 4-way screws and continue from the other pair. Check your switch’s label: a few brands pair the screws top/bottom instead of by color.
Add more 4-way switches in the middle for more locations. The two ends are always 3-ways.

Step 3 of 3

Wire it box by box

Safety first. Turn off the breaker and confirm the power is off with a non-contact voltage tester before touching any wire. Follow your local electrical code; some areas require a licensed electrician or a permit. If you find aluminum wiring, cloth-covered wiring, scorched insulation or more than one circuit in a box, stop and call an electrician.

Switch box 1

Middle switch box

Switch box 3

Light box

Guide

How a 4-way switch works

A 4-way switch has four screws in two pairs and no common screw. In one position it passes the travelers straight through; in the other it crosses them. The travelers from the first 3-way switch land on one pair, and the travelers to the next switch leave from the other pair.

Finding the pairs

On most 4-way switches the pairs are the two brass screws and the two dark screws. Some brands pair them top and bottom instead, so check the diagram printed on the switch or its box. If the light only works in some combinations, the pairs are mixed up.

More than three locations

Add as many 4-way switches as you need in the middle. The two ends of the run are always 3-way switches.

All 4-way switch setups

What you need

As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.

Frequently asked questions

Does a 4-way switch have a common screw?

No. It has two pairs of traveler screws. The common screws are on the 3-way switches at each end.

How many 4-way switches can I use?

Any number, placed between the two 3-way switches. Each one adds another control location.

Why does my 4-way switch light only work sometimes?

Usually the travelers are on the wrong pair of screws: one wire from each 3-way ended up on the same pair. Put both incoming travelers on one pair and both outgoing travelers on the other.

Can I tell a 4-way switch from a 3-way switch?

Yes: a 4-way has four screws plus ground and no ON/OFF markings; a 3-way has three screws plus ground.

More wiring tools