View Full Version : Light won't turn off

September 23rd, 2002, 09:43 AM
Hi. I just installed a new fixture in the home I'm renting. There was an open box but no fixture when I moved in. THe fixture is on a dimmer switch(dial type). I installed the new fixture and now it will not shut off. I'm assuming maybe the dimmer switch is bad. Is that a good assumption??

September 23rd, 2002, 03:50 PM
If the existing switch box only has two wires connected to the existing switch and the existing switch worked then you should have installed a single pole dimmer with only two brass colored screws to connect the hot wires and a green screw to connect the equipment grounding wire.

If your existing switch had three insulated wires connected to that existing switch with one wire connected to a black screw and two wires conneted to two different brass screws then you had a three way existing switch and should have used a three way dimmer switch to replace the exisiting switch.

If there was originally a switch in that box that worked the light on and off and all you did was replace the dimmer chances are you replaced the switch with your new dimmer while the power was on. If this is true good chance is that your fried the new dimmer by installing while energized under load. A dimmer switch should be installed with the power off and no load condition or the c-board will often short out destroying the dimmer.

Take the wires off the dimmer and see if the light will come on. If the light won't come on then touch the wires together and if the light then comes on your dimmer got fried as discribed above.

Hope this helps


September 25th, 2002, 08:46 AM
Hi. Thanks for your response to my question. I did not change the
dimmer switch, only the fixture. The dimmer had been there. On the
fixture I connected Black to black, white to white and the green wire to a grounding screw.

I checked the dimmer last night and there was no juice to it. I hadn't shut any breakers, was just testing with a circuit tester. The light did have juice to it. I then noticed that all the sockets(not lights) in an adjacent room had no juice to them. I checked the breakers and none were tripped. I am now more confused than ever.


September 25th, 2002, 09:06 AM
Check to see if there is power to all of the outlets in the area (top and bottom seperately) with ther dimmer in the on and off position. It is possible that the dimmer never controlled the ceiling light. If the dimmer controls an outlet, replace it with a regular switch or remove it completly (wire nutting through for constant conenction) since a dimmer is not permitted on outlets.

September 25th, 2002, 04:55 PM
Ron is right, however we still have a second problem. I am thinking that you have two problems. YOu said the light won't go off with the dimmer. This tells me the light is hot and working but won't stop working. Then you say the dimmer has no power. Then you say receptacles have no power.

I am suspecting like Ron is that your dimmer controls something other than that light fixture. I am also suspecting that there is not switch controlling that light. I am also suspecting that you have two black wires and two white wires in that light box with the second set of black and white wires being the power to your receptacles. I am also suspecting that you tested from screw to screw on the dimmer and did not register power on your tester, which you wouln't because you are testing from hot to hot in contact with each other. I suspect you did not test from black to white but black to black on the switch or black to white on the switch being a switch leg and not a grounded coductor.

If you have a bare or green ground wire in your dimmer switch test from that bare or green wire to each wire separtaly that is connected to that dimmer switch. See if you have power from either of the two wires connected to the dimmer with the second test lead touching that are or green wire in the box.

Then like Ron said test both top and bottom of the receptacles testing each receptacle you suspect to be dead. Instead of using your voltage tester plug a table light or fan into each receptacle top and bottom using a light or fan that you know works in a different receptacle.

Then tell us how many black wires and how many white wires you found in that light fixture box. I am suspecting that you have two black wires and two white wires in that light box with one black and white being a switch leg going to that dimmer box.



September 27th, 2002, 08:18 AM
Ok guys, here it is. Yes there are two black and two white wires in the light fixture box(and red). The dimmer seems to have no juice at all to it, I have tried all the wires. I have discovered another box that is on the same wall, but stangely placed(much higher than normal for a light switch), when a take off the blank plate, yes I have power to the box, I'll assume that this box had probably had a thermostat in it due to it's height and there is now a thermostat in an area which was an add-on to the house.

With regard to the outlets in the ajoining room, all but one seems to work now. What that's about I'm not sure. I'm going to assume a bad outlet since it seems shaky and replace.

The dimmer outlet has two black and two white wires and red. The dimmer switch has two wires, one connected to the black and one connected to the red.

Hope this makes it clearer. Thanks again for the help.


September 27th, 2002, 02:17 PM
In the light fixture box you said you have a red wire connected to nothing at this time.

In that light fixture box try wire nutting all the white wires together under one wire nut. Then connect the two black wires together in a second wire nut but not including the black fixture wire. Then connect the red wire to the black fixture wire and try it to see if the dimmer turns the light on and off again.

Then tell us what you find. Once we work out this problem then we will attack the second or third problems with receptacles.

Curious, in the dimmer are the two black wires wire nutted together with a jumper wire to the dimmer switch also being black? Then also are the two white wires in the dimmer also wirenutted together in their own wire nut but not touching the dimmer. This is what I am expecting at this time.

Let us know what you find.


September 29th, 2002, 12:54 AM
Eureka!!! Connecting the black light fixture wire to the red wire did the trick!! Can't thank you enough, it's so nice to finally eat dinner and actually see the food!! Tomorrow I'm going to tackle changing the receptacle that appears bad. Hope that's all it is. If not I know where to go!!

Thanks again.
MustangBonnie :D

September 29th, 2002, 09:37 AM
Congrats on your light project success !

As for the receptacle problem I am suspecting that you may have receptacles that have wires backstabbed into holes in the back of your receptacles. If this is true you most likely have a loose connection in one of those back stab connections in the back of your receptacles. Look for bubbling of insulation on the wire where it stabs into the hole in the back of the receptacle. If you find this heat damage chances are you will experience more loose connections connected in this manner. If you find one you will have more. To solve this problem and future problem cut off the damaged part of the wire and then strip it again and connect it to the screws on the side of the receptacle black to brass and white to silver. If you find a receptacle that is also damaged then replace that damaged receptacle. If you found one with a bad connection from the back stab connections then I would open all your receptacles and move the conductors over to the screw connections on the side of the receptacle. This will keep you from having this problem on a second or third receptacle in the future.

Let us know what you find and good luck


September 27th, 2008, 11:08 PM
I had been dealing with a non-functioning 3 way switch and an "always on" light and your advice fixed it - 6 years after it was posted! Kudos and thanks!!