In order to fix cabinet bathroom light fixtures, you'll need to understand the basic skills involved in repairing broken light fixtures. As a general rule, if one of your bathroom light fixtures is not operating properly, the cause can usually be narrowed down to three reasons: the bulb is bad, the circuit breaker or fuse is causing issues, or the switch is the problem.
Below are the steps for testing each of these potential causes. Please follow the steps to determine if one of these simple steps is your solution.
Step 1 - Examine the Bulb
Take a look at the bulb and see if it’s a bad bulb in need of replacement with a new one. Test this bulb by checking to make sure it is screwed into the socket tightly. However, if you verify that this bulb is indeed screwed in securely, take it to another socket that you know is working properly and test the bulb there.
Step 2 - Examine the Socket
Examine the socket by removing the bulb, turning on the light, and verifying the socket is getting power via touching it to a voltage tester’s leads. One connects with the socket’s center brass contact, while the other connects to the bulb’s threaded metal housing. If this test reveals a flowing current, you’ll know you need to replace the bulb. However, if you do not receive a level reading, you’ll need to take the next step.
Step 3 - Examine the Circuit Breaker
Verify that your fuse (or circuit breaker) for this non-functioning light has not been tripped. If for some reason it has been tripped, the breaker will need to be reset or the fuse will need to be replaced before the light can be tested again by attempting to turn it on.
Step 4 - Switch the Circuit Breaker
If you’re still unsuccessful, switch the circuit breaker that is servicing this non-functional fixture. Remove the light switch’s cover plate from the light switch and utilize a voltage tester to see if any of the wires might still be “hot.”
Make certain wires are snugly connected to the switch terminals. Reconnect the cover plate, switch the circuit back to “on,” and retry the switch.
If you’re still not getting light from the fixture, switch the circuit off and test with a continuity tester or multi-meter. If this fails, replace your defective switch; making certain the replacement has the exact same voltage ratings and amperage. Don’t try and fix a switch, by the way, because switches are relatively inexpensive.
If, after taking this last-resort action of replacing the switch, you still cannot get any light out of this cabinet fixture, you likely have a much bigger electrical problem on your hands. And if this is the case, you will probably need the help of an electrician.
With bathroom light fixtures, problems are usually narrowed down to light bulbs, sockets, or circuit breakers. And with a few basic tools and a little know-how, these issues can usually be easily resolved.