Electrical Wiring in the Home/lighting switch


Hello Bob : I recently installed a new light in my bathroom...black to black, white to white and grounded it like I have done on at least 7 other lights in my home. This time however after flipping the power back on and screwing in the bulbs the light came on even though the switch was in the off position and it will not turn off. Thought maybe it was the switch so installed a new one and still the same results. By the way, the switch is connected to the Black and Red wires with the white capped in the switch box. Any help or insight would be greatly appreciated. Thanks


You should always install the new fixture exactly the same as your old fixture.

One of the pair of wires is a switch loop. With the power OFF, use a continuity tester to see which pair of wires show continuity with the switch on, but no continuity with the switch off. (The testers can be found at any home center, and are cheap and easy to use.) The white wire with that pair is actually a hot wire, so put a piece of black tape on it to show it is hot.

Now connect that wire with the tape on it to the black fixture wire.  Then connect the remaining whites together, and the remaining blacks together.
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Electrical Wiring in the Home

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Bob Sponaugle


Just about any home wiring question. (not appliance repair) I have done all kinds of home wiring for myself, including adding a new breaker box, etc. Please, questions from North America only. Please be specific with details.

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