How to Replace a Dimmer Switch Slide Knob

Dimmer switches are available in two types. One has a knob that twists clockwise to make the light brighter and counterclockwise to turn it down. The second style slides up and down to change the lighting. Replacing a faulty dimmer switch is a fairly easy task.

Things You'll Need

• Flashlight
• Screwdriver
• Circuit tester
• Wire cutter
• Wire stripper

Instructions

1. Turn off the circuit breaker that controls the switch to be replaced. Pull the dimmer switch straight out from the faceplate. Unscrew the two screws of the faceplate and remove it.

2. Touch one probe of the circuit tester to the bronze terminal screw and the other probe to the silver screw. If the light on the tester glows or if the display indicates a voltage reading, the circuit is not off. Turn off the correct circuit.

3. Remove the two screws holding the switch to the box. Loosen the terminal screws and remove the wires from the switch. If the wires are broken, frayed or otherwise damaged, cut them. Strip approximately 3/4 inch of insulation from the end of the wires. Attach the wires to the new dimmer switch and tighten the terminal screws. The black wire attaches to the brass screw; the white wire attaches to the silver screw.

4. Push the wires back into the junction box and fasten the switch to the box with the screws provided with the new dimmer switch. Replace the cover plate and turn the switch to the off position. Restore power by flipping the circuit breaker back on. Test the new switch.

Tips & Warnings

• Dimmer switches should not be used to control ceiling fan speed or fluorescent lights.

References

• Bob Vila: Replacing an Electrical Switch
• University of Missouri Extension: Replacing Wall Switches and Receptacles