Wire How To: 4-Way Switch
There are 2 diagrams below, the first one is a diagram of how to wire 3 switches to the same light. You use a combination of two 3-way switches with a 4-way switch in between.
The second diagram shows how to wire 4 switches to the same light by adding another 4-way switch in series.
You can hook up as many switches as you want by just adding 4-way switches, as long as you have a 3-way switch on each end.
The white neutral wires all tie together to supply the light with a return (neutral) path, and the ground wires all tie together as well. If the switches have a ground screw, it would be good to connect the bare ground wires to them as a safety factor, but not absolutely essential for the circuit to work.
Just remember that with connecting two 3-way switches, the hot wire goes to one of them and the switch leg goes to the other one, with two travelers in between.
If the power feed (hot wire cable) and the switch leg (light wires) go into the same box, you can connect the wires like this:
Connect the white neutral wire coming from the light, into the white neutral wire coming from the power feed.
Connect the black hot wire from the power feed, to the third leg of the 3-way switch in that box.
Connect the black wire that comes from the light, to the white wires in your travelers.
Connect the white wire from your traveler in the last switch box, to the 3-way switch there.
Since your light can pick up the neutral from the power feed in the same box, the white wires in your travelers can be used to transfer the switch leg to the last switch in your circuit.
BUT – Be careful to mark the white wire you use for this somehow, like with a piece of black tape toward the end.
Click here for a diagram that will give you a basic idea of what I’m talking about.