Electrical – Adding a 4 way switch to 2 existing 3 Way switches

electricalswitchwiring

Currently I have 2 existing 3 Way switches

  1. Box 1 has 14/2 from power source and a 14/3 run to box 2
  2. Box 2 is 14/3 and 14/2 that runs from the light fixture.

I have added an additional 14/3 to box 2 and run that to box 3. My question is how do I make the connections in box # 2. Do I need to change box 2 to a 4 way switch and then will box 3 be a 2 way switch?

Best Answer

This diagram describes what you want (source), it's just complicated by the box positioning. Normally you do it in a series

  1. Three-way
  2. Four-way
  3. Three-way

I think you can tweak this to make it work.

In Box #1, the incoming hot (the 14-2 black) should connect to the black screw of your switch. Wire the black from the 14-3 to your 14-2 neutral white.

Put your 4 way into Box #2 and wire it as shown in the diagram, but instead of nutting the black wires together, nut the white wire from your fixture (14-2) to one and the black to the other (it doesn't matter which you connect to).