# Adding second light switch to an existing light



## TexasEd (Jun 13, 2008)

I have attic access to the light in question. It is over my game room and it currently is wired for light and ceiling fan on one wall as you walk up the stairs.

Across the room is the door to my bedroom and I would like to add a second light switch to the light there. 

How do I change a single switch light to a double switch light?

Thanks!


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## rjniles (Feb 5, 2007)

You need acess to the existing switch. (Getting access to fixture will not help unless there is 3 wire cable run to the old switch-- doubtful) Run 14/3 or 12/3 cable (if permitted in your local to the new switch location) (size depends on where existing light is on a 15 or 20 amp ckt). Install a 3 way switch at the old and new location.


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## joed (Mar 13, 2005)

This is simple once you get the wire to the new switch.
I am going to skip ground wires in the description. Connect all of them together and to the switch if it has a ground screw.

Remove the two wires from the existing switch. Leave everything else alone. The wires could be both black or black and white. Might even be black and red.
Connect one wire to the common screw of your new threeway switch.
Connect the other one to the black wire to your new switch.
Connect the red and white wires to the remaining two traveler screws of the new switch.

At new switch connect the black to the common screw.
Connect the red and white wires to the remaining two traveler screws of the new switch.


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## rjniles (Feb 5, 2007)

JOED you are assuming the power feed is to the fixture it might go to the switch. If so connect the white of the supply to the white to the fixture (should already be connected this way).Connect the black of the supply to the black of the 3 wire cable to the other switch. At the far switch connect the black of the 3 wire to the common of the switch. Connect the white and red of the 3 wire cable to the traveler terninals at both switches (order or sequence not important).


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## joed (Mar 13, 2005)

rjniles said:


> JOED you are assuming the power feed is to the fixture it might go to the switch. If so connect the white of the supply to the white to the fixture (should already be connected this way).Connect the black of the supply to the black of the 3 wire cable to the other switch. At the far switch connect the black of the 3 wire to the common of the switch. Connect the white and red of the 3 wire cable to the traveler terninals at both switches (order or sequence not important).


It does not matter where the power feed is. You only need to deal with the two wires on the switch. The drawing shows power feed at light but the 3way switch part is the same no matter where the power feed is.


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## rjniles (Feb 5, 2007)

JOED I agree the wiring of the switch is the same but I think a tyro would be confused trying to apply the diagram if he finds the power feed in the switch box.


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## TexasEd (Jun 13, 2008)

Thanks,

I had an idea of the basic concept that you all confirmed.

1. Remove the existing switch.
2. Run a new "traveler wire" between the existing switch box and the new switch box on the other wall.
3. Properly wire in the two new 3-way switches.


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## scooterfern (Aug 15, 2008)

*would like further info*

I want to add a 3 way swith and the wires coming in are red and black.The red is attached on top of the old switch and has a jumper going to another swich that controls portch light.Which screw on new 3 way do I attach this red wire to and then the black?the white is attached to white going tothe other switch also.The wire going to the light from the switch is a 3 way wire but is not a 3 way switch.In the junction box above light red is tied to a black that goes toward the next room.Any advice would be helpful.


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