Install a Dimmer Switch Install a Dimmer Switch

Installing a dimmer switch is a surprisingly easy task that can change the feel of a room in as little as 20 to 30 minutes. By following these simple steps, you'll be enjoying your new lighting in no time. If you haven't already, now may be a good time to check out our article on a few things you should know about dimmer switches.

The tools you will need for this project are:

  • Screwdriver
  • Wire Strippers
  • Needlenose Pliers
  • Voltage Tester (Don't worry, you don't need an expensive one. Most hardware shops sell inexpensive ones for as little as a few bucks.)


Additional materials that will make the job go easier include:

  • Electrical Tape
  • Wire Nuts
  • Dimmer Plate (Not all companies supply one with the switch, so check before you leave the store.)


Although dimmer switches come in various styles, the installation procedure is mostly the same from type to type.

1. The first step with every electrical job is turn off the power to the circuit you're working on. This step is the most important and should never be skipped - it not only protects you from injury, but it also protects the dimmer switch from potential damage.

  • Tip: After turning the breaker off, tape a piece of electrical tape over the breaker to ensure that no one will turn it on while you're in mid-installation.


2. Unscrew the faceplate from the existing switch.

3. Unscrew the existing switch.Gently pull the switch out of the box. Over time, wiring may have become loose or brittle on the old switch.Wires may disconnect while pulling the switch out - another good reason to have the power off!

4. Use the voltage tester to double check and make sure the circuit is off.

5. Unscrew the wires from the terminals on the old switch. Some switches may have been installed using the pressure connectors on the back of the switch. If that is the case, you may be able to wiggle them out or just clip them off with the needlenose pliers. Throw the old switch away.

6. Use the wire strippers to cut the bare wire off right below the insulation. Then, use the wire strippers to strip 3/8" insulation off the wires.

  • Tip: On the side of most strippers is a guide that will show you how much insulation should be stripped.


7. In most cases, the dimmer switch will come with pre-wired and pre-stripped wires on the back. Simply take one wire on the dimmer switch and one wire from the wall box and hold them side by side. With the needlenose pliers, twist the exposed part of the wires together. This gives a better connection and helps prevent one of the wires from slipping out of the wire nut. Tighten a wire nut over the wires. Repeat with the other wires. You should have one dimmer wire connected to the wall wire, and the other dimmer wire connected to the other wall wire.

8. Take a 3" length of electrical tape and wrap it around the wire nut where the nut meets the wire. This helps protect against a wire being accidentally grounded. Repeat with the other set of wires.

9. Gently fold the wires back into the wall box. It helps to bend them in an accordion style fold for an easier fit. Dimmer switches are larger than regular switches, and thus it may take some careful working of the wires to make it fit well. Also, if the switch shares the box with other components, it would be wise to turn the power off to them before this step for safety reasons.

10. Once the dimmer switch is set in the box, screw it into place.

11. Screw the new faceplate on the dimmer switch. Make sure the dimmer switch is in the OFF position.

12. Back at the electrical panel, remove the electrical tape and turn the circuit(s) back on.

13. Slowly turn the dimmer switch on to test proper working order.

This is a fairly easy task, and if followed properly, these steps will help the Do-It-Yourselfer do the job safely and correctly - not to mention save money by doing it yourself!

Click here to purchase dimmer switches.

Dave Donovan is a freelance copywriter living in Atco, N.J. An electrician for 15 years, an injury forced him to pursue his true passion - writing.


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