# basic question - single pole switch in a 3-way setup



## Jim Port (Sep 21, 2007)

To replace a 3 way toggle switch with a dimmer you would need a 3 way dimmer.

If you install a single pole dimmer it will not work properly.


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## dbpass (Aug 25, 2010)

Thanks for the reply. In what way will it not work properly (trying to learn a little bit here)? Will it not work even if I leave the second switch that controls the light in a fixed position?


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## AllanJ (Nov 24, 2007)

You can install a two wire dimmer in any 3 way switch box so as to become the sole switch for the light. A dimmer with three wires on it will work on some but not all 3 way setups even if you leave the other switch in a fixed position.

You will have to tell us which box the power comes into and describe preferably with pictures the wiring in each of the switch boxes.

It may take a little back and forth and a little twenty questions on this forum but we should be able to help you out.


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## dbpass (Aug 25, 2010)

Excellent, that is helpful info, thank you. I'll take a look at the current setup and post photos if I'm not sure what's going on in there. Thank you!


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## joed (Mar 13, 2005)

If you install the single pole dimmer it needs to be connected to the common and one of the travellers. The other switch will need to be in the proper position to make it work.


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## macdonald (Aug 5, 2010)

IF the power feed and the switch leg are in the same box then your good to just use those two wires for you switch.

If the power is fed at one box and the switch leg is at other box, open the box up that you do not want to use as a switch anymore. Marrett the wire under the common and one of the travellers(ie the red wire). Put a marret on the last single wire as not to short anything out. Buy a blank coverplate and close the box up. At the other end you will be putting the red traveller on one of the screws of the single pole switch and the wire on the common of that switch on the other screw of the single pole switch.

Home this helps and easy to understand.


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## secutanudu (Mar 15, 2009)

This diagram helped me learn how 3-ways work when I was learning...(it's animated, so keep looking at it)


http://www.indepthinfo.com/3-way-switch/3-way-switch-explained.shtml


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## dbpass (Aug 25, 2010)

Thanks for the responses and diagram.

I decided to just go ahead and order a 3-way dimmer for the switch. The installation went well and it appears to be functioning properly.

I do have a new question now about the other switch that controls that light. I did not install a dimmer on that switch, it's a regular on/off switch, which I assume is a 3-way. I did notice some "crackling" sound when I turned that switch on though, so I have since left it in the off position.

My question is, if you install a dimmer on a 3-way switch, does the the other switch need to be a dimmer too? Thanks!


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## SD515 (Aug 17, 2008)

Thanks for the responses and diagram.

I decided to just go ahead and order a 3-way dimmer for the switch. The installation went well and it appears to be functioning properly. Good to hear :thumbsup:

I do have a new question now about the other switch that controls that light. I did not install a dimmer on that switch, it's a regular on/off switch, which I assume is a 3-way. I did notice some "crackling" sound when I turned that switch on though, so I have since left it in the off position. Can be typical in some switches. Its a small arch thats happening when the contacts are close to each other but not actually touching. 

My question is, if you install a dimmer on a 3-way switch, does the the other switch need to be a dimmer too? Thanks! No


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## joed (Mar 13, 2005)

A three way does not have an ON or OFF position. That is all dependant on the other switch.


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