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coopns 04-30-2012 01:01 PM

Three romex into recessed light box - light won't turn off
I have three romex coming into one arm of the recessed light. 1 from a new recessed light, 1 from switch and 1 from not sure where. I connected all the blacks/whites/grounds to the recessed light but the light doesn't turn off when I flipped the circuit back on.

When I took the existing light out it had two romex going in but funny (or not) thing was one of the reds wasn't hooked up, it was just sitting there, no wire caps and not attached to anything. I tried it once with the red in with the blacks and one without and neither would turn the light off.

The other romex that came from the switch didn't have a red. Light worked fine.

Please advise

hammerlane 04-30-2012 01:15 PM

How many cables and what wires associated with each cable are in the switch box location.

Also when you use terms like other romex, this light, that light, that wire, this wire, the box , the wire. One never knows if the other romex, this light, that light, that wire, this wire, the box , the wire is the same item you are referring to.

kevinp22 04-30-2012 01:26 PM

Are you familiar with "switch loops" and how they work

Also, I assume this light worked fine until you or someone else added the "new recessed light"? does this new light turn on/off or is it stuck on too?

JulieMor 04-30-2012 03:18 PM

The light doesn't turn off because it's hooked up to a hot or another switch that is on and not the switch leg (we use the term "legs", not "arms") that feeds the existing fixture.

The red wire isn't used and should not be connected but it should be capped with a wirenut in the event someone hooked a hot to it while not knowing what they are doing. :huh:

How was the existing fixture wired before you added the new fixture? All you had to do was find the wires connecting to the can light and use those to feed the new can light.

If you don't remember how it was wired, you may have to get a voltage tester and trace out the wires. That would require opening for access both the existing and new fixtures as well as the switch box.
  1. Identify the hot. In the existing fixture, test across two wires at a time then do the same at the switch. Check voltage against both a neutral and a ground to make sure you have the hot. The switch should be in the off position for this test.
  2. Identify the neutral. In above step, if you get voltage across a known hot wire and a white wire, the white is the neutral.
  3. What's left is your switch leg but NOT the unused red wire. Use either a continuity tester (breaker turned off) or voltage tester to make sure. If you do the latter, turn the switch off and test the power at the light (should be off) then turn the switch on and power at the light should be on.
  4. Make sure the hot is only connected to the switch and not the can lights.
  5. Connect the switch leg to the hot wires that feed the can lights.
  6. Connect the neutral to the neutral wires that feed the can lights.
  7. Connect all ground wires.
  8. Test before you put everything back together.

coopns 05-02-2012 04:07 PM

So I gaver a whirl.

So I was incorrect, 3 romex coming into the box arm of the recessed light. Two have Red.
1 from the new can (w/b/n)
1 from the switch (W/B/R/N)
1 from I think the bathroom (w/b/r/n)

I though I tried every config you suggested and more (no tester).


I disconnected both red and let them hang not connected to anything and the light still stays on.

So what are the red doing?

andrew79 05-02-2012 05:12 PM

how many wires are in the switch box. Any chance your dealing with a 3-way situation? The wiring adds up for that.
which red was capped off in the box?

coopns 05-03-2012 08:19 AM

The switch box has a black and red. It also has a white but is just taped off. Not connected to anything. (The previous owner was a half arsed electrician as I am finding out)

Any suggestions now?

andrew79 05-03-2012 08:28 AM

you get your incoming power. whatever wire that may be tie it into the red going to the switch. Tie the black from the switch into the light. I'm assuming one red was attached in the box from what you said earlier so black from washroom to red from switch black from switch to light, white from washroom to light.and red from washroom goes unused as it did before.

hammerlane 05-03-2012 08:29 AM


Originally Posted by coopns (Post 910977)
I have three romex coming into one arm of the recessed light........ When I took the existing light out it had two romex going in

Very confusing post. You say you have three cables coming in then say you have 2 cables coming in.

How do you know they are coming in and not going out?

I believe you need to provide some photos of the cables and wiring at the switch and lights.

JulieMor 05-03-2012 09:40 AM


Originally Posted by coopns (Post 913439)
The switch box has a black and red. It also has a white but is just taped off. Not connected to anything. (The previous owner was a half arsed electrician as I am finding out)

Any suggestions now?

If I understand what you've said correctly, all the whites in the can light in question are connected, the red wire was disconnected and not capped and the black wires were all connected. Correct?

Then at the switch you have a red, black and white. The white is capped and the red and black are connected to the switch. Correct?

If so, the red wire is mostly the switch leg and somehow got disconnected inside the can wiring housing. That is the wire that needs to be connected to the black wire that feeds the can lights.

If that doesn't work, pictures tell a thousand words.

Also, if you intend to DIY your electrical, buy a decent voltage tester/meter. Here's a video to show you what you can do with it:!

coopns 05-03-2012 01:20 PM

3 Attachment(s)
I think I have tried every suggestion here, I might be able to get a feeler thing, not wigs later this afternoon.

Here are some pics.

Looking straight at it...

Left - coming from switch b/w/r
Top - coming from second can light b/w
Right - coming from (thought was bath, don't think it is now) b/w/r

Two wires hanging down are from the can.

The light is on a dimmer switch, does that factor in?

And does the capped off white in the switch box need to be connected to something?

frenchelectrican 05-04-2012 01:34 AM

I have a feeling something is not adding up right in here so here what I will suggest ya to do next.,,

Take a photo of that dimmer switch but at differnt angle try to get into back of the box so I can see how many pairs of cables are in there and do you any chance you have second switch in that room ??

That one reason why I ask due if only single NM cable in the switch box then it was oringally wired for three way switch loop so that why I am supecting there is second switch is used as well so try to find it if you can.

( note : I am not suprised that when from time to time someone will bury the second switch box it can get ya pretty good with some cussing along the way )

Right now just tempory remove the dimmer switch if still good shape and put a toggle switch in there for now ( just trust me you will see why in a second.) due it will simpleifed the testing prodcure due the dimmer switch will throw out odd voltage reading and either DVM or NCV ( non concat voltage tester ) Tester will read funky if still on dimmer so with convernal toggle switch you either have full voltage reading or none so nothing between the two for safety and easier to troubleshooting.

I know you mention capped off white in switch box where the dimmer switch is located if that is true I am pretty sure it was used as three way switch operation.

Right now you will need either DVM or NCV tester ( with NCV tester becarefull with faux postive due some are very senstive. )

This what I will suggest is the right pairs ( at the luminaire location ) spread it apart and test to see which one is a correct pair either black et white or red et white so check it out.

once you verify it and mark it down or use a small peice of tape to let ya know then what you will do next is all the ground conductors ( bare ou green ) wirenut together first and push it back in the box then do netural ( white ) all of them wirenut together then for power for luminaire as long you are using switch loop this step will give you a small headache but I will break it down.

Now let start with a left red conductor ( that go to the switch box ) take that to the right black or red conductor ( depending which way you verify the power there ) wirenut together then fold it back then take the black conductor from left side to the luminaire black conductors and fold it back and ya should be done.

This is assumed that you have live supply source if the second switch box is either hidden or just wired direct.

If you found second switch box then stop and take a photo and post it back asap one of us members will help you the correct way with it.

Bon chance. ( good luck )


coopns 05-04-2012 07:27 PM

1 Attachment(s)
Obviously out of my league (way out). So I called a electrcian and of course figured it out. But not quite like I expected, I really did try every combination I could think of and most of the recommendations here - I appreciate the effort. I did hold out for awhile because I do like to figure stuff out myself but I couldn't frig this up.

R black to L black
R white to L white and white from top (other can)
R red nothing
L red to can black and black from top (other can)

Of course it makes sense after he explains it six times and draws a pic.

Thanks again.

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