Wiring question


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Old 12-08-16, 09:28 PM
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Wiring question

Well, working on the ceiling light fixture, I came across this. 2 white wires and 2 black wires from the ceiling. Black wires are fine and connected, not I'm trying to figure out what the extra white wiring is all about.
Already have the ground attached to the junction box as well.
Attached is the picture, any ideas what's going on here?
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Old 12-09-16, 03:46 AM
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You have two cables entering the ceiling box (which should be either round or octagonal) It is possible the white wire that has a black pigtail on it is from a switch loop. I would say the two black wires from the ceiling box should be capped together and the black pigtail attached to the blacks from the fixture. You will need to do some testing first. I know you took pictures before you disconnected the wiring.......oops. OK, remove the light fixture from the black wires. Separate the black wires. With an analog multimeter ($10 or so at box stores) test each black to ground for power. Put a piece of tape on the hot wire and cap it off. Set your meter to ohms, turn the breaker off and probe the other black wire from the box and the hanging black/white combination wire with the switch "on". You should get a reading. If you do, that is a switch loop, and my above theory is right. Cap the two blacks together in the ceiling box. Connect the two whites to the whites in the fixture. Remove the black pigtail and put a piece of black tape on the remaining white wire (denoting it to actually be black) and attach it to the two blacks in the fixture. Restore power and check switch and light operation.
 
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Old 12-09-16, 03:59 AM
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Before following Larry's very good instructions check the other half of the circuit, the switch. Does the switch have a black and white wire on it? Are those the only wires in the switch box? If so then yes you have a switch loop.

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Old 12-09-16, 04:13 AM
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Good catch, Ray. My instructions would necessitate that first and foremost.
 
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Old 12-16-16, 04:42 AM
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I will be getting to this today, I guess I should write my will first, but I'll just skip that part and go straight to the lighting - at this point, everything in this house has been a royal f... up.

Thanks for the replies, will try to adhere to them as best I can while holding the black wires in one hand.
 
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Old 12-16-16, 05:16 AM
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You turn the power off at the breaker first thing. That way you don't have to worry about the black wire.
 
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Old 12-16-16, 07:45 AM
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Was this working,did you disconnect anything?
 
 

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