3 way light switches are for lights that you want to control with more than one switch, like at the top and bottom of some stairs. They’re simple to function and extremely convenient in usage, but sometimes they may become defective or malfunction, becoming both an inconvenience and a major safety hazard.
The 3 way circuit
In order to repair the circuit, you’ll need to know some basics about how the circuit is wired. The 3 way switch is the main player in the circuit, having one common terminal and two travelers terminals. The common terminal is connected to a hot wire that usually leads to the lighting fixture or the main board, while the traveler wires lead to the other three way switch.
Repairing the circuit
The most common problem you’ll encounter is having a defective three way switch. You should replace both switches as the same time, since it’s often very difficult to find out which switch is defective and additionally, if one has failed, the other can’t last much longer either.
When replacing the switches, you need to attach the common wire (black) to the common terminal on each new switch and reattach the insulated wires (white) on the travelers terminals. If you connected the right wires to the right terminals, then you should simply be able to replace the switches into their boxes and turn on the power to see the switches work.
If the circuit still isn’t working, then you most likely incorrectly attached the incorrect wires to the terminals. In this case, you’ll first want to use a multimeter to check for the hot wire; there should only be one hot wire in this case, which will be your common wire. Attach that to the common terminal of the first switch and then turn off the power. Go to the other switch and set your multimeter for continuity (or infinite resistance) and then ground one probe and touch the other three wires. The common wire should be the only one to register resistance and that will now be your common wire for the other switch. Attach the appropriate wire, and it should work.
If you followed the steps above and still could not get your 3 way circuit to work, then you may want to consider finding an electrician to fix this circuit, as there may be other factors or wiring issues. TalkLocal can help you find an high quality electrician in just minutes. It’s fast, easy and best of all, free!
