I've lost my light installing mojo.

December 25, 2006 10:43 PM

We decided to replace an ugly old chandelier today. After turning off the breaker and taking off the chandelier, I noticed there are black, red, white and green wires. The house is circa 1968. From what I can tell there used to be a fan/light. So I hooked up our flourescent dome by matching the wire colors and capping the red wire. Unfortunately, it didn't work.

So then I connected the black wire on the lamp to the black and red wire in the ceiling. I'm going to stop now before I kill myself or burn our house down, but I wish I knew what was going on. Did I burn out the ballast on the light? Is there non-standard wiring? I've installed fans and lights before. What should I do next? Thank you.

posted by mecran01 to home & garden (14 comments total)

I suggest using a meter to check electrical flow to each wire. Good luck.
posted by alltomorrowsparties at 10:47 PM on December 25, 2006

Sounds like it may be hooked up to a three-way switch (or someone used that wire but didn't use one of the wires). There are a couple ways it could be wired up, then. Do you remember how it looked before you took it all apart? That would help.
posted by wemayfreeze at 10:51 PM on December 25, 2006

To clarify: black + white would be hot + neutral, green would be ground and red would be the three-way hot carrier. If I remember correctly.
posted by wemayfreeze at 10:54 PM on December 25, 2006

I'll get a meter and check it out. In the original wiring on the ceiling box the white and green were combined and the black and red were also connected. The black/red were attached to the black wire on the original chandelier. I am embarassing myself at this point with my ignorance...
posted by mecran01 at 10:59 PM on December 25, 2006

I've done some house wiring and I'm having trouble following you... so I wouldn't say you are embarrassing yourself.

Just figure it out with a voltmeter. If you don't have one already, you can probably get one for about $10-20.
posted by Doohickie at 11:21 PM on December 25, 2006

Or call in a qualified electrician and, when he's fixing it, ask him to show you what's going on.

You'll know the light's properly wired and you'll learn for the next time.
posted by Nugget at 3:16 AM on December 26, 2006

I will definitely get a voltmeter this morning and probably call an electrician. Here is a hopefully clearer description:

The wiring coming out of the ceiling consists of:

white + green, combined ------>non-black wire on original lamp

red + black, combined --------->black wire on original lamp


My wiring:

white------>white
green------>green
red------->wire nut
black------->black

Also, the lamp says it won't work if it isn't grounded properly, so that could be it.
posted by mecran01 at 7:06 AM on December 26, 2006

Good lord. Call an electrician--you don't know what you're doing, and this could turn out to be unbelievably unsafe in both the shrot (electrocution) and long (faulty wiring) terms.

Seriously. Call a professional; you are in over your head.
posted by dirtynumbangelboy at 7:07 AM on December 26, 2006

And for the next time that you do something like this, when you pull the old fixture, take some pictures with a digital camera before disconnecting the wires. This way, it's a lot harder to forget how things were hooked up.
posted by plinth at 7:27 AM on December 26, 2006

Assuming this is a switched light and not a pull cord you could also pull out the switch and examine the wiring - it may give you some clues.

Also, are you sure that the red/black wires go to the same place when they leave the ceiling box, and that one doesn't travel to another box to provide power? That is more likely if it isn't a switched fixture, since otherwise any further outlets would be switched with the light.
posted by true at 7:59 AM on December 26, 2006

On the contrary, dirtynumbangelboy.... if mecran01 proceeds cautiously, there's no reason not to do this job. This is precisely the kind of thing I did when I started doing my own work. And just this morning I repaired an electric oven, saving myself well over $100 if a serviceman had done it.

I would recommend buying a book on household wiring (I have the Readers Digest guide to home repair and it was a great help in my early days.
posted by Doohickie at 10:46 AM on December 26, 2006

You probably have a switch loop: the power goes to the light fixture, and the hot lead is patched through a 2 wire circuit that goes to the switch -- *both* sides of which are hot to ground when the switch is on -- it's the only time the Code permits a hot white (identified) wire.

If there were more than 2 words in that paragraph you didn't understand; I'll second "call an electrician" -- especially since I wouldn't expect a red wire in a switch loop situation -- or indeed, in a lighting situation like that at all...
posted by baylink at 1:14 PM on December 26, 2006

Ok, here's the followup. The red wire was there because there used to be a fan there, I am surmising, as there is another in the kitchen 15 feet away.

The first mistake I made last night was working on it at night. I didn't see the green ground wire wedged in the back of the box. There was a pale green wire which was actually "white." which I mistook for the ground.

I bought a voltmeter this morning, flipped the breaker and the red and black wires were hot. I hooked up lamp black to ceiling black and the light worked, but was not connected to the wall switch. It just stayed on.

So I disconnecte the ceiling black from lamp black, nutted ceiling black and connected ceiling red to lamp black, green to ceiling ground, white to ceiling white.

Everything works and there is no burning smell. On the downside, the light isn't as bright as I had hoped, but it's not going anywhere at this point.

Fashioning a metal hook to hang the fixture from the ceiling box made a huge difference, a little trick I keep forgetting. I also keep forgetting to pre-insert the hanger screws in the ceiling box, which makes everything fun and easy.

Thanks all. If there's a fire and I survive I'll be sure to post here.
posted by mecran01 at 4:55 PM on December 26, 2006

> the light isn't as bright as I had hoped

Well, that makes me nervous, but I guess "a fan" is a good reason for the other wire.

Good luck with that; if we dont see you post for a couple weeks, we'll call the fire department...
posted by baylink at 9:14 PM on December 26, 2006