How to Install a Dimmer Switch: Step-by-Step Guide

Replace a wall light switch with a dimmer switch safely. Tools, materials, and step-by-step instructions.

Home & DIY

FigsiT Project Rating

Take care

Turn off the breaker and confirm the power is off with a voltage tester before touching any wire. Aluminum wiring needs special connectors and is usually an electrician's job.

Safety gear: Non-contact voltage tester, Safety glasses

Permits and zoning: Swapping a fixture usually needs no permit, but new wiring or circuits often do.

Tools Required (5)

Not sure what something is? Tap it to see a picture.

Materials Needed (3)

Tell FigsiT your exact setup and get your personal tools list, materials, and steps in seconds.

Step-by-Step Instructions

1.
Turn off the power at the circuit breaker.
2.
Remove the existing switch cover plate using a flathead screwdriver.
3.
Unscrew and remove the old switch from the electrical box with a Phillips #2 screwdriver.
4.
Use a voltage tester to ensure no power is present in the box.
5.
Take note of the wire connections on the old switch for reference.
6.
Disconnect the wires from the old switch, keeping them separated.
7.
Strip approximately 3/4 inch of insulation from the ends of the house wires.
8.
Connect the ground wire from the dimmer switch to the ground wire in the box using a wire connector.
9.
Connect the black wire from the dimmer switch to the black (hot) wire in the box using a wire connector.
10.
Connect the red wire from the dimmer switch to the remaining wire in the box using a wire connector.
11.
Carefully fold the wires back into the electrical box.
12.
Secure the dimmer switch to the box with the provided screws.
13.
Attach the new switch plate over the dimmer switch.
14.
Turn the power back on at the circuit breaker and test the dimmer switch to ensure proper operation.