Electrical – Turning two-way switches into three-way

electricallightingwiring

Picture in the link is in my garage. I have four 14/2 cables. All whites are nutted together. 2 blacks are nutted together, and 1 going from that nut to each both switches.

The below pic has three 14/2 cables. Two blacks are going from the wire nut to the switches, and 2 blacks are being run from the wires to the switches. Then my 14/3 wire is pictured.

Not sure how to run the wires to make this work.

This is what I am thinking. The whites from the new cable get wire nutted in and the red goes on one of the screws in both outlets. Keep that black jumped from the wire nut to the switch, and have the black from the 14/3 go on the other terminal on the switch?

enter image description here

enter image description here

Best Answer

14/2 is a cable. It contains 3 wires if you count ground. I will use those words that way.

On your existing switch, note the black that goes to the other blacks. That is always hot. The other wire, mark it with red tape. That is switched-hot.

Run a /3 cable from this switch to the other switch. Mark the black and white wires with yellow tape on both ends. Those are travelers.

In this box, connect the /3 cable's red wire to the wire you just marked red.

Wire up your 3-way switches as follows.

  • the 2 yellow traveler wires go to the 2 brass (yellowish) colored screws on the 3-ways.
  • now there is one wire still not connected in each box. That goes on the 3-way black screw.

And we're done.

This simplicity brought to you by the maker of colored electrical tape.