How To Install a Dimmer Switch

Cut the power to the light switch by flipping the circuit breaker or removing the fuse at the main panel.

Unscrew and remove the light switch cover plate.

Unscrew the screws that anchor the switch in the electrical box, and remove the switch. It will now be attached by only three wires.

Two of the wires going into the switch will be similar (either both black or one white and one black), while the third will be either a green or bare copper ground wire. Loosen the screws that hold the two similar wires to the switch, then remove those wires.

Now remove the ground wire.

Cut the ends of the three wires coming from the wall. You’ll use the wire leads that come already attached to your dimmer switch.

Strip an inch of insulation off the wires coming from the wall. If your ground wire is bare, you won’t need to strip it.

Use a twist-on wire connector to attach the green ground wire from the dimmer switch to the ground wire coming from the wall. Hold the wires next to each other, and screw on the connector in a clockwise direction.

Using another connector, attach one of the other two wires from the wall to either of the two black wires on the dimmer switch.

Using another connector, attach the remaining wire from the wall to the remaining black wire on the switch.

Screw the dimmer switch into the electrical box.

Reattach the light switch cover plate and tighten its screws.

Attach the knob to your dimmer.

Restore power to your switch. Now let that light shine!