Electrical – Adding back removed 3-way switch from 4-way setup

electricalmultiway-switch

I made a terrible mistake. I removed a 3-way switch from a 4 way switch setup without labeling the existing wires. Now the light the switch was attached to doesn't come on. I was going to put a blank in place of the switch but now I just want to put the switch back the way it was. I had just capped the three wires separately. I'm very sure the black and red wires were connected directly to the switch. The white wire probably was somehow twisted with all the other white wires from the other switches.

There is a 4 gang box upstairs with switches in it controlling four different lights. All lights are on the same circuit. All white wires except one are twisted together in this box. One white wire from a 2-wire (leftmost) is not connected to anything and has tape covering the end. I assume power comes in and is hooked into every light there. The switch I tried to remove from this box is a 3-way switch connected with a 3 wire. Downstairs is another 3-way switch connected with a 3 wire. (I assume they are connected together.) Red wire is top left, black is top right and white bottom right. Also downstairs is 4-way switch with two 2-wires coming in, blacks on left whites on right. The light controlled by all three switches is closest to this 4-way switch. There is one 2-wire coming into the light, I presume from the switch close to it. Directly above this 4-way switch is the 4 gang box upstairs.

Is it correct that all I have to to is add another white wire to the removed 3-way switch and twist it and the white wire from the capped white from the 3 wire together with all the other white wires and hook up the same way as the 3-way switch in the basement?

4-gang box with 3-way switch removed

Best Answer

  1. Power off.
  2. Pick any 2 of the capped wires formerly attached to the 3-way.
  3. Nut those two together.
  4. Leave the third wire nutted independently.
  5. Power on.
  6. Throw any other switch in the 3/4 way group. Does the light turn on or off?
    • all other 3/4-ways work correctly -- fail*. Pick a different pair and go to 1.
    • lights do not work in either position -- success. The two nutted together are the messengers.

Mark both messengers with yellow tape (or other appropriate marking) -- messengers are interchangeable, so you don't need to distinguish them from each other.

The two messengers go on the brass screws of the 3-way switch.

The remaining wire is common and goes on the black screw.

* Or, if you just want to eliminate that 3-way, you can stop right here and you are done.

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