I have a very odd light problem. We took down the ceiling to move a light. We have two switches in the dining room that control two lights. After moving the one light, I tested the light I moved and it is working fine. I simply physically moved the box, I didn't do any new wiring. I'm not sure I tested the other light but it was working before the ceiling came down. Now, the light I moved is working but the other light doesn't come on. The odd thing is that the working light is getting power from the non-working light.

Another odd thing is that the non working light has odd wiring in that there are two white wires coming out of each cable but no ground wire. One of these white wires seems thicker and is partially stripped at the base. The working light has regular two-wire with ground.

Why would this light not be working?

Current light

Light before removal

Switch closet to non-working light

  • "I simply physically moved the box, I didn't do any new wiring" --- It would be very odd if you could move a box without doing any wiring. can you explain what you mean by move a box ? – Alaska Man Feb 19 '18 at 1:46
  • @Alaska man What I mean is that I didn't run any new cable, I just used the existing old cable. – fullerm Feb 19 '18 at 2:09
  • FYI- none of this is odd, you've got a bad connection or mis-wire. We also need to see how the switch is wired and what colors are there too help you sort this out. The 3-wire connection is likely for the switch loop from what we know now.... – Tyson Feb 19 '18 at 2:14
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    The loose black and white wire in the top photo surely go to the lamp. Lamps need neutral. So presumably the white loose wire goes into the neutral bundle with those "gypsy neutrals", which would validate they are indeed neutral. I would still hit them with a voltage tester, just to be sure, the stupid is strong with "the last guy". – Harper - Reinstate Monica Feb 19 '18 at 20:18
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    I'm a little cautious to say "it'll just work" because obviously the guy ran the neutral for a reason i.e. he needed one more wire. Anytime you're in a 3-way circuit it can get a little complicated because it is almost impossible to keep track of which color wire has which function. Therefore I am fastidious about using colored tape, and I redrew that drawing to color for function. Yellow are the two travelers which land on brass screws, always color both ends of a wire at the same time. – Harper - Reinstate Monica Feb 19 '18 at 20:31

The existing wiring is as in this diagram:

enter image description here

So the solution was to tie the white sheathed wires with a copper wire to make them ground again. I tied in another black to the existing blacks (one was cut off previously for some reason) and hooked the black and "white" (black wire tied in with the other whites) to the light. All works fine now.

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    No, you shouldn't do that -- that's a good way to get zapped! – ThreePhaseEel Feb 19 '18 at 23:21
  • @ThreePhaseEel How so? – fullerm Feb 21 '18 at 0:34
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    Now you have current flowing through ground wires, which puts anything connected to them "live" – ThreePhaseEel Feb 21 '18 at 0:43
  • @ThreePhaseEel No, the ground wires are all ground again exactly as they should be. – fullerm Feb 21 '18 at 1:26
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    @ThreePhaseEel the jerry-rigged "neutral" wire in the light box was tied in with the other grounds in the switch box. This was probably changed by an electrician previously who found the original configuration unsafe. – fullerm Mar 10 '18 at 23:52

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