How to Test a Light Socket

If you replaced a burnt-out bulb, but the new bulb doesn’t work either, is it a bad new bulb, or is the socket faulty?

To test for light socket problems, you’ll need to determine if there’s a complete circuit allowing the socket to receive electricity. Electrons must flow in an uninterrupted path from the power source and back for the socket to work. Therefore, testing the socket is the next step after you realize a burnt-out bulb or tripped breaker isn’t the problem.

How to Test a Light Socket with a Multimeter or Voltage Tester

You will need a non-contact voltage tester or a multimeter to test if a light fixture has power. A non-contact voltage tester can test for voltage by measuring the electrical current fields without touching the contacts. A multimeter gives much more detailed information and will require touching the touch probes (or leads) to the electrical contacts.

If there is no power, you know there’s a fault in the light socket or the wiring leading to it.

Testing the Socket While It’s On

First, test if your voltage tester or multimeter works properly on a bulb or outlet you know is working. 

To test an individual light socket, turn on the power. Press the non-contact voltage tester to the tab at the bottom of the socket. It should flash or beep if there is voltage. 

To use a multimeter to test the individual light socket, set it to read AC voltage. Touch one probe to the brass power contact tab at the bottom of the socket. The probe should be centered and not touch the contact and sidewall simultaneously. Touch the other probe to the silver shell where the bulb threads into it without touching a power source at the same time. Don’t let the probes contact one another.

If there isn’t power for the individual socket, test the wiring underneath. Remove the mounting screws, lower the socket, and press the voltage tester to the hot screw (attached to the black wire).

For the multimeter, connect the black probe to the ground screw first (attached to the bare copper wire or metal electrical box). Then, touch the other probe to the hot screw terminal (attached to the black wire). It should read around 120V. 

How to Read the Multimeter

If the multimeter reads 120V, the socket and the circuit are working. But, if no reading shows, the light socket isn’t receiving power, and the neutral wiring is likely faulty. You’ll need to further evaluate the problem by turning off the breaker and taking the socket apart so you can check the wires connected to it.

Testing a Light Socket with the Breaker Off

Switch off the circuit breaker to the socket. Then, test the socket by attaching the continuity tester clip to the hot screw terminal (black wire) and touching the probe to the socket’s metal tab. If the tester doesn’t respond, the socket must be replaced.

However, you can continue testing the socket by clipping the continuity tester to the neutral metal screw terminal (this is the white wire lead). Then, touch the probe to the socket threads. The tester should show a reading. If not, then there’s no question you need to replace the light socket.

Diagnosing the Problem

When a light socket is not working, it can be hard to determine the source of the issue. There could be damage to the socket itself or a flaw in the wires and cables leading to it. If the meter doesn’t pick up current from the brass and silver tabs on the back of the socket, you may have a wiring problem. Wires could be corroded, stripped, or frayed.

It is unsafe to perform wiring work without electrical experience; the best option is to have an electrician diagnose the problem and make the appropriate repairs.

Contact Black Hills Home Services

We have trained, licensed, and bonded electrical technicians who can quickly determine why your light socket isn’t working. Our team can fix the problem no matter how big or small. We can complete repairs right every time using the highest-quality materials and equipment. 

We will find the cause of the problem, and then we’ll determine what likely caused it. It may be that replacing the wiring will be enough to fix it, but if there was a catalyst to the wiring or socket failing, we’ll find ways to address it so it won’t happen again. To request light fixture repairs from an electrician in Olympia, Washington, contact us today.