I Replaced An Overhead Light; Now The Light Switch Trips The Circuit Breaker When The Switch Is Turned OFF!?

I didn't write down the old wiring configuration before I took down the old fixture. The light box is actually wired for dual lights. There is a set of wires (one black, one tan & one ground) on one side of the light box , and then there is an identical set on the opposite side. The new fixture that I attached doesn't have multi-colored wiring; it simply has two copper wires sheathed in brown vinyl and a copper ground wire. When I wired the new fixture to the box wires, I put two old black wires and one new copper wire together, two old tan wires with one new copper wire, and the two old ground wires with the new ground wire. When I turned the breakers back on, the light came on & seemed fine. However, when I turned off the wall switch that controls the light, it tripped the breaker. I reset the breaker, the light came on; I turned the switch OFF, the breaker tripped. I've re-wired many different combinations & replaced the switch; OFF still trips the breaker instantly. Any advice??

7 Answers

  • 1 decade ago
    Best Answer

    You probably reversed the common and 120 volt wiring to fixture. I'm assuming you only took caps off the wires of the old fixture. tan is probably your switching leg and the switch also controls an outlet in the room the key is to hold the fixture black wire to one of the black wires in the box and the white wire of the fixture to the metal box that will tell you where your power is coming from,if you hold the black of the fixture to the other black in the box while holding the white to metal you will find it's dead. take one tan into your hot black the other tan into the fixture and remaining black in box.whites all together.

    remaining fixture wire goes to metal IE equipment ground. you will find you are turning on/off fixture and an outlet in room.

    your 120v does not come from switch to fixture it's up in the box.ie tan wire makes voltage from box to fixture and outlet draw a path of travel relax see it you'll get it

  • 4 years ago

    It's pretty obvious that it is the last fluorescent light fixture that is causing the problem. It is likely a short, but finding it might be time consuming, unless you can remove the fixture. If the fixture is removed, there should be no tripping. Then test the fixture with a simple continuity tester to find the short. Make sure you are careful taking the fixture wires out of the wire nuts if you have not shut off the fuse to the whole circuit. You can also examine the wires in the ceiling to see if there are bare spots that might touch. You may want to look for dampness that might also be causing shorts.

  • 1 decade ago

    the last guy confused the heck outta me, but it sounds like you have basically by-passed the switch and made the light box a full time outlet coming from the panel. Then when you flip the switch you are sending juice back through one of the other sets of black/tan wires you hooked together shorting out the breaker, try using only 1 black 1 tan and tying the grounds together...good luck

  • 1 decade ago

    White wires are neutral unless they are marked otherwise such as black tape wrapped around it an inch or so from the end. Green are ground or earth. Bare copper are also. All other colors, usually black and red are hot. So, colors to colors. Whites to whites. grounds to grounds. Electrical books on wiring are readily available. Please get one for yourself. If you were willing to jump right in to this project I'm sure with a little instruction and a picture or two you'll do just fine. Happy project and please be careful.

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  • Anonymous
    1 decade ago

    where do the extra wires in box go? is there another switch somewhere? switch you are using just single throw? even if there was double fixture before there still should only be one black, white, ground. the other three must go to something else. best check where they go.

  • Jim W
    Lv 7
    1 decade ago

    Since you are not able to solve this yourself, it will need to be fixed by a qualified professional electrician. Sorry we can't do it on line, but this needs a hands on examination.

  • Anonymous
    1 decade ago

    you could burn your house down doing electrical repairs with out the know how, but good luck and buy a smoke detector.

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