How to Add a Dimmer Switch

Use a wire stripper to cut 1/2-inch of plastic from the wires.

Dimmer switches are added to change a room's ambient feel by increasing or decreasing the light level. Though there are different types of dimmers available (toggle, dial, touch pad). They all fit into a standard wall switch box and connect to standard 12/2 or 14/2 electrical cable. By starting with a few simple safety procedures, an existing light switch is easily removed and a dimmer installed in less than a half hour with no previous electrical knowledge.

Things You'll Need

• Screwdriver
• Wire cutter
• Wire stripper
• Wire nuts

Instructions

1. Turn off the circuit breaker in the home's breaker box that powers the light circuit being worked on. Turn on the existing light switch to make sure the light fixture is now receiving no power. If the light comes on, the wrong breaker has been turned off.

2. Unscrew and remove the faceplate of the existing light switch that will be replaced by the dimmer. Also remove the two screws holding the switch to the wall box. Carefully pull out the switch from the box.

3. Unscrew the terminal screws holding the two black wires to the back of the switch. Pull out the black wires. The white wires will be joined together with a wire nut in the back of the box. The green ground wires will either be connected to a ground screw in the back of the box, or a wire nut.

4. Cut off the bare ends of the two black wires using wire cutters Strip off 1/2-inch of black plastic from the end of the black wires using wire strippers. Hold the end of one black wire together with the end of one of the dimmer switch's black wires. Screw on a wire nut, making sure the bare copper ends of the two wires are fully inside the wire nut. Take the remaining black wires from the box and dimmer and hold the ends together. Screw on a wire nut.

5. Remove the screw/wire nut holding the box's two ground wires together in the back of the box. Place the end of the dimmer's ground wire with the box's two ground wires, and attach them together with the box's ground screw/wire nut. Push all wires into the back of the box. Secure the dimmer to the box with the two screws. Attach the faceplate to the front of the dimmer by installing the two screws. Turn on the circuit breaker.

Tips & Warnings

• Some dimmer faceplates require no screws to hold them in place, but simply push in place onto the front of the dimmer.

References

• Easy 2 DIY: Installing a Dimmer Switch
• Don Vandervort's Home Tips: How to Install a Dimmer Switch