Troubleshooting - New Ceiling Light

I just replaced a ceiling light fixture (operated by a wall switch), but the new light stays on when I throw the circuit breaker. I was told that I have an "open line," but it appears that I have attached all wires (include the grounding wire) properly. I thought it was the light, but the old light also will not turn off when I reattached it. Any suggestions? Thanks.

To Clarify for Juice: When I turn the breaker ON, the light goes on (while the switch is in the off position). I tried switching the wires but the light still stayed on. Any further thoughts? Thanks.

[Edited by dgage on 01-16-01 at 01:23]

 

The only explanation I can offer, is you are not flipping the right circuit breaker, OR, the circuit breaker is defective. If all other outlets in the same room are de-energized when you flip the circuit breaker, then the light has to be on a different circuit.

Recommend you have someone watch the light while it is on, and someone else start flipping circuit breakers, one at a time, until you find which circuit it is on. Then label it on the circuit breaker panel.

 

A little clarification, please. When you "throw the circuit breaker", do you mean turn it OFF? The first thing that came to mind is that you threw it ON and the switch won't turn the light off. Let us know if this is the case, because I have the feeling that you swapped hots in the ceiling box. The one that went to the switch and the one that go to the black lead on the light fixture must be reversed if my guess is correct.

Juice

 

The black wire ought to go to the switch.

 

My only guess is that you said "when I throw the circuit breaker," you really mean "when I throw the light switch."

The most common cause of lights not responding to the light switch is the failure to understand wiring in which line power comes first to the light fixture. If you wire such a fixture with white to white and black to black, the light will never go off as long as the breaker is on. Normally what happens next is that the breaker trips when you throw the light switch on. As of right now, 4 million posters on this forum have had this problem.

To wire this correctly, you'll have to connect light fixture white to the white from the breaker, the light fixture black to the black from the switch, and the black from the breaker to the white from the switch. I hope you can figure out which cable comes from the switch and which from the breaker.

I realize my explanation doesn't quite fit your description, but I don't think any explanation fits your description. So faced with such a dilema, I modified your facts to fit my answer. I also made some other assumptions, such as the fact that you have two black and two white wires at your fixture.

P.S. If you respond again, please post a reply rather than editing your earlier post.

 

In my first reply I think my assumption was correct, particularly in light of your edit. I think power from the breaker goes first to the ceiling box, in which case a white from the black pigtail in that ceiling box would go down to the light switch carrying live juice, then a black returns from the switch to the light fixture's own black wire. If the fixture/switch circuit was not wired following this standard color convention then the above will not follow what you actually have going on in the ceiling box but you still can fix it. Look in the switch box and identify the two wires that connect to the switch. Identify the other two ends of those wires where they come out in the ceiling box. One should be black, and the other should be either red or white, most often it's white. The white should get its power from the main black "hot" group in the ceiling box and connect to the switch at the other end. The white sends power to the switch. Now the black in the switch box gets connected to the other terminal on the switch, and at the other end of it gets connected to the fixture's black wire. I think you connected a single black wire, which was connected to the main black "hot" group in the ceiling box, directly to the fixture's black wire, completely bypassing the switch. I sure hope that makes sense to you, and that it will help you solve this problem. Good Luck.

Juice

 

In my earlier posting, I did not clarify that the original ceiling light worked fine from the switch.

When I installed the new light, that is when I encountered the problem of the light always being on when I engaged the circuit breaker. The same problem arose when I reattached the old light. It seems as though I may have done something to the wiring itself (the only other change was installing a new ceiling strap). Thanks for any help.

 

dgage,

Nothing you said in your most recent post would cause me to change my recommendation of my prior post. To quote myself:

"To wire this correctly, you'll have to connect light fixture white to the white from the breaker, the light fixture black to the black from the switch, and the black from the breaker to the white from the switch. I hope you can figure out which cable comes from the switch and which from the breaker."

Please give this a try and report back.

 

I think what everyone is trying to tell you is that you have more than one black and more than one white in your light fixture box. We think that you mixed up these wires when you installed the fixture.

Come back in and tell us how many blacks and how many whites are in you light fixture box not counting the black and white fixture wires attached to the fixture.

Wg

 

Being an avid DIY 'er I have been down this road--John N stated it simple and correct. You must know which wire (hot) comes from the breaker--not the switch--to get this right. My best friend is a multi-meter when I am messin with power. Get one, there're cheap, and don't guess it--test it!

 

Amen to redneck. Home Depot sells a multi-tester for about $10. It has AC, DC and Ohms (This is a must for continuity tests.) And it comes in a beautiful bright yellow! I simply wouldn't be without one. Nor should anyone doing electrical work. Since electricity is invisible most of the time (exceptions: short circuits and lightning), the tester can see what you cannot. Think of it as a seeing-eye dog! (And a gaurd dog, for that matter...) Thanks for bringing that up, red.

Juice

 

Since dgage has a light that is always on when the breaker is on, he should know that the cable the light is connected to now is the one that comes from the breaker. His light is his multimeter.