How to Wire a 3-Gang Switch (with one power source)
A 3-gang switch is simply three separate switches housed in a single electrical box. It is used to control three different lights or fixtures from one location.
This guide assumes the most common scenario: you have one power source (a "Line" wire) entering the box, and you want to distribute that power to three switches, each controlling its own light fixture (a "Load" wire).
Tools and Materials
3-gang electrical box
(3) Single-pole light switches
3-gang switch cover plate
Wire stripper
Screwdriver (Phillips and flat-head)
Needle-nose pliers
Non-contact voltage tester
Wire nuts
Short (6-inch) pieces of wire for "pigtails" (same gauge as your house wiring, typically 14-gauge)
Understanding the Wires in Your Box
Before you start, you must identify your wires.
Line (Hot): This is the single black wire that brings power from the circuit breaker.
It will be the only wire that is "hot" (shows voltage on your tester) when the breaker is on and all switches are off. Load (x3): These are the three wires (usually black or red) that go out to your three separate light fixtures. They are only "hot" when their corresponding switch is in the ON position.
Neutral (White): These are the white wires.
They provide a return path for the current. Standard switches do not connect to them. Ground (Green/Bare): These are the bare copper or green-insulated wires.
They are a critical safety feature.
General Wiring Steps
Turn Off Power: Go to your breaker panel and shut off the power to the circuit.
Use your voltage tester on all wires in the box to ensure they are all dead. Connect All Ground Wires (Green/Bare):
Take all the ground wires in the box (from the power source, from the three load cables) and connect them together with a wire nut
Include three (6-inch) "pigtail" ground wires in this same bundle.
Connect the other end of each pigtail to the green ground screw on each of the three switches.
Connect All Neutral Wires (White):
Take all the white neutral wires in the box and connect them together with a single wire nut.
Gently push this bundle to the back of the electrical box. (Standard switches do not use the neutral wire. Note: Smart switches often do.)
Connect the Line (Hot) Wire (Black):
This is the most important step. Identify the single Line (hot) wire coming from the power source.
Create three (6-inch) black wire "pigtails."
Use a wire nut to connect the single Line wire to all three of your pigtails. You will have 4 wires in this one wire nut.
Connect the other end of one pigtail to the Line terminal (often brass-colored, sometimes labeled "Common") on the first switch.
Repeat for the second and third switches, connecting one pigtail to the Line terminal of each.
Connect the Load Wires (Black/Red):
Identify the three Load wires (each one going to a different light fixture).
Connect the first Load wire to the remaining screw (the Load terminal, usually black or bronze-colored) on the first switch.
Connect the second Load wire to the Load terminal on the second switch.
Connect the third Load wire to the Load terminal on the third switch.
