# HowTo: Adding two exterior lights + switch, piggyback new switch off existing switch?



## Sliver (Nov 18, 2008)

in the existing switch
you should already have a wire nut on the white so all you need to do is add the new wire that's feeding the new switch.
remove the black from the switch, put that in a wire nut with the new wire to the new switch and a short "pigtail" that goes to the existing switch

in the new switch box
wire nut the neutral from the source to the neutral that is going to the lights
black from the source connects to one side of switch
black going to the lights connects to the other half the switch

in the first light box
wire nut the white from the switch with the white to the 2nd light box with a short pigtail to the light fixture
wire nut the black wire the same as you did with the white

in second light box just hook the black and the white to the fixture


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## ghost (Mar 30, 2009)

perfect! thanks!
i really appreciate it.

what type of wiring should i get?

looks a lot simpler than i was worried about.

and this would allow both switches to work independent from each other, correct?
meaning the new switch would only control the new lights and the existing switch would continue to only control the existing light?


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## joed (Mar 13, 2005)

The above drawing assumes you do not have a switch loop. If you open the existing switch and only find a black and white wire then you can not do it.


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## ghost (Mar 30, 2009)

joed said:


> The above drawing assumes you do not have a switch loop. If you open the existing switch and only find a black and white wire then you can not do it.


if this is the case, what would another option be?
there would be no other way to run off of the power source of the existing switch?
i could not install a new switch for the existing that would facilitate this?


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## Sliver (Nov 18, 2008)

ghost said:


> perfect! thanks!
> i really appreciate it.
> 
> what type of wiring should i get?
> ...


You will be able to control the new lights with the new switch and the old light with the old switch.

You will probably want to get Romex. You will need to know what size breaker is on that circuit: 15A breaker get 14/2 romex, 20A breaker get 12/2 romex.

If your switch has only two wires in (1black and 1 white taped black) its a switch loop which will require:
Running a three wire cable or from your existing light to the existing switch. at the existing light connect the red to the fixture wire nut the blacks together, wire nut the whites together with a pigtail. In the existing switch box connect the red wire to the switch, wire nut the blacks together with a pigtail to the switch, wire nut the whites together. the rest is the same...

or

Run a new 2 wire cable from the light, make sure you connect to the hot black wire not the switched black wire, to the new switch.


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## johnnyboy (Oct 8, 2007)

If you have a switch loop (only the HOT wire is in the switch box, not the neutral/ground) then it will like like this:









In that case you need to tap into the neutral/ground, and run it to the new lights as well. 
Then you tap into the source BEFORE the old switch, and send that to the new switch. That way both switches always have power. It will look like this in the end:










it might be easier to pull the neutral/ground back down through the old switch box, meet up with the HOT supply and send all three to the next switch, the HOT goes to the new switch while the neutral/ground just pass right through the box upto the new lights. Pretty simple stuff, I'm sure you got it!


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## joed (Mar 13, 2005)

You can't do that. You must have the neutral and the hot in the same cable. You also need another wire to the switch box anyway so might as well put in the proper one.


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## ghost (Mar 30, 2009)

johnnyboy said:


> If you have a switch loop (only the HOT wire is in the switch box, not the neutral/ground) then it will like like this:
> 
> 
> 
> ...



sounds simple enough! thanks guys!


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## theatretch85 (May 17, 2008)

ghost said:


> sounds simple enough! thanks guys!


The diagram JohnnyBoy posted is NOT code compliant and is UN-SAFE! Please do not wire it up this way, follow the advice of joed and the others who have posted here to run the proper wire! If you have to run a new wire down to a new switch box, you can just as easily run a second cable down to the new switch and pull power from somewhere else.


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## ghost (Mar 30, 2009)

theatretch85 said:


> The diagram JohnnyBoy posted is NOT code compliant and is UN-SAFE! Please do not wire it up this way, follow the advice of joed and the others who have posted here to run the proper wire! If you have to run a new wire down to a new switch box, you can just as easily run a second cable down to the new switch and pull power from somewhere else.


ah ok, i see.
then i'll avoid his diagram.
thanks anyways johnnyboy.

i appreciate it theater tech.
but *sliver*'s explanation is valid? as well as his second in case if it's a switch loop?


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## Sliver (Nov 18, 2008)

ghost said:


> ah ok, i see.
> then i'll avoid his diagram.
> thanks anyways johnnyboy.
> 
> ...


The difference is that all conductors of the circuit need to be run together.
Your neutral and ground can't go one way and then have your hot go off to the switch by its self.

If used johnnyboy's diagram just take the hot in to the first new light and make a switch loop to the new switch.

There are different ways to wire this, its up to you to decide whats easiest, and to make sure its too code and safe.

Did you ever look to see if it is a switch loop, or is power feed through the switch box?


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## ghost (Mar 30, 2009)

Sliver said:


> Did you ever look to see if it is a switch loop, or is power feed through the switch box?


no, i have not yet looked as it's behind the drywall.
i want to get a plan together and all materials + time needed before actually cutting into the drywall and starting.


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## Gerrymans (Apr 19, 2009)

*switch loop*

I am trying to add an addional switch to control an additional light and have not been able to get it to work. After reading several other postings i realized i am trying to tap into a switch on a switch loop. Can someone tell me if this is possible and the best way to do it.


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## joed (Mar 13, 2005)

You should have started your own new thread. The only way to do it is to find an unswitched ower source to use for your new light.


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