3 way switch

Last Edited By Krjb Donovan
Last Updated: Mar 11, 2014 05:19 PM GMT


I have bought a modular home ,at the top of the basement stairs they installed a 3 way swith and it goes to one light and they coiled up the rest of the wire though the floor. they said that the white wire is the common. I took that wire over to another 3 way switch and added more lights after that switch. how should that second switch I installed be wired to make all the lights work.

       Thanks Brent 


How many wires are included with the "rest of the wire"?

The term "common" in a 3-way circuit means that it gets connected to the screw on the switch that feeds the light. That screw is a different color than the other two screws.

The other two wires are travellers. They get connected to the two screws that are the same color. If you have questions about that simply look at the existing 3-way switch that is already wired.

If you only have 3 wires and a ground, you will need to get your power from the existing light to add more lights.


I have a 3 way switch when turned off and I use my tester one screw tests hot. Only one screw. Can I pigtail off this hot screw to get power for a fan I want to install Thank you in advance



You need to find the feed wire in your three-way system. That would be a 14-2 wire that when removed give you 120 volts. I would not suggest a beginner or home owner try to figure this out. It is a bit more complicated to understand and is easily confused with the travelers in a three-way.


I want to put a ceiling fan in with a single pole switch.I have a 3 way switch I would like to pigtail off of to get power to the fan.Is this possible if so could you please explane the wiring.I would think I could find the hot wire and pigtail off of that Tkank you in advance


You need a constant hot wire and a neutral. Which means the power would have to originate at the switch you want to tap into.

How do you know if you have this? You will see one set of wires with just a black, white, and ground. If you take a voltage reading across the black and white you will have 108-120 volts.

The 108-120 volt reading will be there no matter the positions of the three-way switches.

If you do not have this then you will have to find another suitable source or run a new line.


QUESTION: I have one 3way switch controlling several receptacles.The switch does not appear to do anything.In both positions the power remains on with only a slight loss of power during switching.Do I need a 3 way switch or should I replace it?

ANSWER: I doubt if there is anything wrong with the switch. It looks like the switching circuit is contaminated with a circuit that is on all the time. Are any of the outlets only half controlled by a switch? If so, the tab must be broken on the dark side. This does not apply if the whole outlet is controlled by a switch. EVERY outlet must have the correct tab configuration for ANY outlet to work with the switch. If that is not it, a wire that should be connected to one of the switches is connected to a power source.

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QUESTION: Thanks---I do not understand why I would have one 3 way switch to control the receptacles? I belivieve the red traveller would go to the switched outlets but where would tha black traveller go and what is it's purpose?


It does not sound like you have a 3 way switch. It sounds like you have split outlets. One half on the switch, and one half on all the time. If you have red wires on one dark screw and black wires on the other dark screw, it is a split outlet. If that is the case, then remove the tab between the two screws. None of the outlets will work on the switch until all the tabs are removed.


I have a regular wired 3 way switchs, one at each end of the stairs, but the light is at the bottomof the stairs and the top of the stairs is dark at night. Can I connect a 12-2/g to the switch at the top of the stair switch and connect another light to it so it will turn on at the same time as the orginal light. If so i will need a diagram showing what to do with the blach and white wires that will be new tothe switch box. I am pretty good with wiring and basicly understand wiring, with the exception of this problem. Thanks You!


Your options depend on how your circuit is currently wired. I need to know at what point does the power come in and what switch feeds the light.

You should have power entering at either switch or the light. One switch feeds the other switch, and one switch feeds the light.

Knowing this will determine what options you have.


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