Troubleshooting a Light Fixture Wire

A woman installs a light fixture.
  • 2 hours
  • Beginner
  • 45
What You'll Need
A new lightbulb
Voltage tester
Needlenose pliers
Flathead screwdriver
New switch
New light fixture

It used to be that only an electrician could troubleshoot a light fixture wire. You would have to wait for one to arrive, and pay an expensive hourly minimum, and a trip charge. Now you can save yourself time and money by fixing the problem yourself. In most cases, the issues with a broken light are caused by the light bulb, the fuse, or the switch. The following is a step-by-step guide to help you isolate and repair the problem.

Replace the Bulb

Try replacing the old light bulb with a new one. You may even want to remove a bulb from a fixture you know is working and try it in the faulty fixture. If the light turns on, your job is done.

Check the Fixture

If the good bulb does not work, try testing the outlet with a voltage tester. There are 2 types of voltage testers, contact and non-contact, and both can be purchased and possibly rented from your local hardware store. A non-contact tester is adequate for this type of work. Press the end of the tester onto the brass contact at the center of the fixture. If the fixture is working properly, the tester will buzz and light up. If this happens, the fixture is receiving power, and a new bulb will work fine. Make sure you install the correct wattage rated bulb for that fixture.

Check the Circuit Breaker

If the tester does not light up and buzz, there may be an issue with either the fixture itself or with the circuit breaker. In the breaker box, each circuit should be labeled with the corresponding areas of your home. Check to see if the breaker has been tripped. If the breaker toggle is not firmly sitting in the ON position towards the center of the panel box, it is tripped. If it's tripped or pointing towards the outside of the electric panel box, slide it all the way "OFF" and then all the way towards the center in the "ON" position. The light should turn on.

Check the Wiring

If this does not solve the problem, check the wiring at the light switch box. First, turn off the correct circuit breaker in question. Use a small, flathead screwdriver to remove the light switch cover plate. Do not touch the wires before first using the voltage tester to see if any of the wires are still hot. Then check to make sure the wires are correctly fastened to the switch terminals. The wires should be wrapped around the screws on the side of the switch and screwed down securely to the terminals. Return the faceplate cover back over the switch. Turn the circuit breaker back on and test the light.

Replace the Switch

If the light still does not work, turn the circuit breaker back off. Remove the faceplate cover and replace the switch with a new switch. You will want to make sure the new switch has the same amperage and voltage ratings as the previous switch (as well as the same color as the faceplate). Be sure to properly wrap the wires around the correct terminals and screw the terminals down. Turn the circuit breaker back on and test the light.

Replace the Fixture

If the light still does not work, there may be an issue with the wiring in the light fixture itself. Turn the circuit breaker back off and remove the light bulb from the fixture. Remove the cover for the fixture and make sure the wires are properly secured to the terminals.

If the light still does not work after trying all these methods, you should call an electrician to help troubleshoot the issue.