Tuesday, November 23, 2010

Light switch won't control light fixture anymore?

I changed a light fixture in my room. The light switch had controlled both of the light fixtures in the room, and now it will only control one. The other light just stays on all the time. It is a ceiling light, so there isn't a switch on the actual light fixture. How can I get the light switch to control both lights again??Light switch won't control light fixture anymore?This is simply a guess so bear with me. Did you plug the light fixture into the wrong plug? For instance, our switch controls both TOP receptacles but the bottom ones are on all the time. In other words, go plug the fixture into the bottom plug if it's plugged into the top one and vice versa.

Light switch won't control light fixture anymore?If I understand this correctly,

you shoud have 2 sets of wires(black, white, then ground) if there are 2 fixtures on same switch. the white wires are travelers and should be wired together. You then should be left with 2 black wires(hot) they should go to the fixure, it doesn't matter which wire as all your doing is completing the circuit in the run of the two lights.

FYI: remember to turn the power off firstLight switch won't control light fixture anymore?First, I'm assuming that you're in North America. If not, don't rely on this.

You don't say which of the two fixtures is currently controlled by the switch. I'm guessing it is the %26quot;old%26quot; fixture.

Most likely in the box behind your new light fixture there are 3 white wires and 3 black wires and 3 bare wires. The fixture also has a white, a black and a bare or green ground wire.

These are:

1 black %26quot;hot%26quot; wire coming from the power panel

1 white neutral wire coming from the power panel

1 black and 1 white wire coming from the other light fixture

1 black and 1 white wire coming from the switch

1 bare wire coming from each of the above

The trick is to determine which white/black pair are coming from the switch. Be sure the Breaker serving your room is turned OFF at the power panel.

Pull the wires out of the box but do not disconnect any yet. There will be two or more white wires joined. There will be two or more black wires joined. There will almost certainly be a black and a white wire joined. The white wire of this pair is likely the white coming from the switch. Connect the black wire of your new fixture to this black/white pair. Connect the white wire of your new fixture to the all white/white group. If there is a green or bare wire on your new fixture, connect it to a ground screw on the metal box in the ceiling.

Turn the breaker back on and all should check out. Turn the power off again while you stuff the wires back in the box and screw your fixture back into place.

Good luck. Light switch won't control light fixture anymore?reread you question, it's confusing. you should call the ceiling light #1, and the other one #2. then explain which one you worked on, and which one is staying on. the mix up is probably where you connected the wires when you replaced the light, but determining which wire it is will be the problem.

if i had to guess what you did, (it's the ceiling light that is staying on), i'd guess that you mixed up the hot lead with the runners to the switch. it may be that the power was run to the ceiling light box, then split to the lights, and a wire was run to the wall switch to control them. in this case the runners to the switch, one white wire and one black, would both be hot. if you assumed that the white wire was neutral, and connected it to the other white wires, that might have caused what is now happening.

what you need to do now is determine which wires go where, and what they do. you'll need to open the ceiling light box, the switch box, and either the outlet or light box for the other light and then determine where the power enters the lighting system for the room, and which pairs of wires go where. the first thing that you would do is determine the power source and then tape off the hot lead before you start testing the other pairs of wires.

i would start by turning off the power at the fuse or circuit panel and then opening the wall switch, remove the switch from the box, and see how many wires are in that box.

1) if the wall switch has just one black and one white wire in it, both hooked up to the switch, then the power does not enter the light system there. this means that this white wire is a hot lead (runner) at it's other end. some electricians will cover the wire with black electrical tape at both ends to signify this, but many don't.

2) if on the other hand, you find that there are two sets of wires in the box, the whites and the grounds connected, and the black wires connected to the switch, then this would probably be where the power enters the light system to the room.

now, if you found the first wiring i described, you will need to open the ceiling light fixture and determine which pair of wires are the ones that run to the light switch box. identify them both as hot leads, (i'd cover the white lead with black tape), connect one of them to the power source (a single black wire), and the other to the supply (all the other black wires to the light(s) and or outlet for the other fixture). all of the white wires and all of the ground wires would be connected to themselves, whites to whites, and grounds to grounds.

of course to determine the hot (supply) wire you would have to identify the wires to the other fixtures, through the proccess of elimination, the one that does not go to the fixtures would be the supply. the ony other way to determine it would be to separate all of the black wires from each other, make sure they aren't touching anything or each other, then turn the power back on, and working with live electricity and a test light, determine which wire is the hot wire. i wouldn't reccomend doing this unless you are familiar with working with live wiring and comfortable doing so.

at this point, you may just want to turn off the power to the room, and call an electrician, if all this sounds too confusing. and i might not have even described the way your house was wired, it could have been done another way altogether.

good luck, if in doubt, call in an electrician.

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