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I have lots of wires coming from my ceiling box. I guess because of two wall switches that turned on old fixture. Check the image below.

Analog voltage detector "beeps" on black wire in the middle and black&white tied pair on the right. It doesn't react on white wires on the left.

How to connect my new light fixture that has just two wires: black and white (plus green which is ground)?

enter image description here

Thanks

  • What was the old light fixture connected to? Also, your description needs some rewording or punctuation - it's hard to tell what's going on. – JPhi1618 Jan 18 '16 at 19:29
  • Thanks for feedback. I changed post a bit. Hope that will help – Andrey Jan 23 '16 at 18:00
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EDITED: Now that you've posted a picture... ;-) Still test to confirm this, but it looks to me as if:

  • The 2 blacks and 1 white that are connected, are feeding power through the light box to downstream outlets and also sending power to the switch (on the white wire). Wrap the end of this white wire with black tape or mark it with a black permanent marker. It's a hot wire.

  • The lone black wire with a wirenut on it is the power coming back from the switch. This one is hot when the switch is on, dead when the switch is off. Connect this to the black/hot lead on your light fixture.

  • The 2 white wires are the neutral (grounded conductor) from the incoming circuit, and the neutral serving the downstream outlets. Connect these to the white/neutral lead on your light fixture. I'd probabaly add a short pigtail so there's only one connection to the neutral on the light fixture, and also so it's that much more obvious which wire(s) connect to the fixture.

  • Thanks. I have analog voltage detector for now and it "beeps" on black wire and on black&white bundle but do not react on white. – Andrey Jan 23 '16 at 17:27
  • To clarify: should I connect neutral wire from fixture to just ONE of those two neutral from the box bundled together? Or I just can cap all three of them? – Andrey Jan 24 '16 at 3:28
  • You want to connect all three, because that continues the neutral (grounded conductor) path to the additional outlets "downstream." That's part of the reason I'd probably just add a pigtail (connect a short 4" to 6" white wire to the other two), then connect the pigtail to the light fixture. – Craig Jan 24 '16 at 4:36
  • Everything works! But I notice that bulb subtly flickers when switch is off. Is it because poor connection (or isolation) somewhere? – Andrey Jan 24 '16 at 19:37
  • Is the wall switch brand-new, or is it the old switch? It's possible that the switch is broken. – Craig Jan 24 '16 at 20:42
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While most people can make educated guesses about what the coloring means on electrical wires, I would suggest using a multimeter to actually test the wires and through a process of elimination, determine your live wire, the return, and ground wires. Too many ceiling boxes are wired oddly to have confidence in guesses based on wire color.

The live wire will have a proper voltage reading (in AC) to the other two bundles when the switch is on. The return wire will have a proper voltage reading (in AC) to the live wire, when the switch is on, and will have no voltage reading (in AC) when the switch is off. The ground wires should have a proper voltage read to the positive regardless of the switch position.

If you can't identify which wires in your outlet using the above rules, odds are something is really off with your wiring, and you probably should call in a professional.

Keep in mind that testing live wires can be very dangerous, so you need to take proper precautions. If you don't know what those are, call a professional.

  • For your situation, you can probably assume that the two connected (and capped) wires are the same, because electrically, they are. – Edwin Buck Jan 18 '16 at 19:30
  • You would do well to edit your post to eliminate the terms "positive" and "negative" with respect to AC mains wiring. Usage as you are is confusing and actually incorrect for AC circuits. – Michael Karas Jan 18 '16 at 19:32
  • @MichaelKaras Sorry, too much electronics work muddling my home wiring brain. Thanks for pointing it out. – Edwin Buck Jan 18 '16 at 19:40
  • Thanks for answering. I have analog voltage detector for now and it "beeps" on black wire and on black&white bundle but do not react on white. – Andrey Jan 23 '16 at 17:28

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