3-Way Dimmer Switch Wiring

A 3-way dimmer replaces one of the two 3-way switches. Its COMMON lead takes the incoming hot, its traveler leads connect to the 14/3 travelers, and the other end stays a regular 3-way switch.

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

Grounds: join the bare copper wire in the 14/2 cable bringing power in, the bare copper wire in the 14/3 cable to switch box 2 and a short bare copper pigtail to the 3-way dimmer’s green ground screw under one wire nut.
Neutral splice: join the white wire in the 14/2 cable bringing power in and the white wire in the 14/3 cable to switch box 2 under one wire nut.
3-way dimmer, COMMON lead or dark screw → the black wire in the 14/2 cable bringing power in.
3-way dimmer, traveler lead/screw → the black wire in the 14/3 cable to switch box 2.
3-way dimmer, other traveler lead/screw → the red wire in the 14/3 cable to switch box 2.

Switch box 2

Grounds: join the bare copper wire in the 14/3 cable to switch box 1, the bare copper wire in the 14/2 cable to light box and a short bare copper pigtail to the 3-way switch’s green ground screw under one wire nut.
Neutral splice: join the white wire in the 14/3 cable to switch box 1 and the white wire in the 14/2 cable to light box under one wire nut.
3-way switch, COMMON screw (the dark/black one) → the black wire in the 14/2 cable to light box.
3-way switch, traveler screw (brass) → the black wire in the 14/3 cable to switch box 1.
3-way switch, other traveler screw (brass) → the red wire in the 14/3 cable to switch box 1.

Light box

Light fixture, black lead → the black wire in the 14/2 cable to switch box 2.
Light fixture, white lead → the white wire in the 14/2 cable to switch box 2.
Light fixture, ground lead or screw → the bare copper wire in the 14/2 cable to switch box 2.

What you need

LED dimmer switchSingle-pole and 3-way capable, rated for LED and incandescent bulbs.

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Smart dimmer (neutral required)Wi-Fi dimmer for boxes with a neutral wire.

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No-neutral smart dimmerFor switch boxes without a neutral.

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Non-contact voltage testerConfirms the power is really off before you touch a wire.

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3-Way Dimmer Switch Wiring

Which setup do you have?

Flip the switches

Wire it box by box

Switch box 1

Switch box 2

Light box

Other dimmer switch setups

What you need

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