Fixing 3 Way Switch & 4 Way Switch Wiring Problems
Solving 3 Way Switch & 4 Way Switch Wiring Problems
Existing 3 Way Switches
Virtually every house has at least one set of three way switches. They may be at the bottom and the top of stairways. Often they can be found at either end of a hallway. If one breaks or you wish to replace them with more decorative switches, you can often confuse the wires.
If you hook up either one or both of the three way switches incorrectly, they will not operate properly. One switch may turn the lights on and off, while the other switch does nothing.
Which Wire is What?
Let's assume you are in a mess right now. The switches don't work. You don't have a continuity tester. Here is how to fix them. The first thing that must be done is to identify the two common wires. There will be one in each switch location. One of these wires is 'hot' continuously. The other one leads directly to the light fixture. Isolating them is usually not too hard.
Locate the circuit breaker in your electric panel that powers this light circuit. Turn it off. Go to each switch, take the cover plate off and remove the switch from the electric box. Unhook the wires from the switch. Don't allow them to touch one another. Hopefully you will also have two neutral (white) wires wire-nutted together in each box. Remove the wire nuts from both joints but keep the white wires together. Make SURE no black wires are touching each other or the white wires! Turn the circuit back on. Now it's time to be CAREFUL.