When a ceiling light fixture doesn’t work

If your ceiling light fixture doesn’t work, let’s talk about one I worked on last weekend. It wasn’t my first time doing that. I ended up replacing the fixture, but then I fixed the broken fixture afterward.

First things first: The Bulb

I started with the simplest thing, replacing the light bulb. It’s best to use a light bulb you know works. Take a bulb from a nearby fixture and try it. When we tried three different bulbs and none of them worked, I took the other bulb in the room and used it. Two of the three bulbs that didn’t work in the bad fixture turned out to be bad themselves.

I’m not sure why people keep bad bulbs around but I know I’m not the only one who’s done that. LED bulbs do last longer, by the way. When you go to get new bulbs, be sure to take your burned-out CFL bulbs with you. Home-improvement stores have a recycle/disposal box at the front of the store, and most types of light bulbs are cheaper there than at, say, the grocery store.

Important safety precautions

If it’s not your bulbs, there are a few other things to check. But before we move on, let’s talk safety. Before proceeding further, cut off power to the light fixture from the circuit breaker or fuse box.

Let’s get back to fixing stuff.

Ceiling light fixture doesn't work
When the brass tab in the center of a light socket gets mashed down, it causes problems. Bend the tab up to at least a 15-20 degree angle. If it’s badly discolored, it can also cause problems.

Check the brass tab

I would have saved myself a lot of effort if I’d tried this trick second. There is a brass or copper tab inside the light socket that engages the center tip of the bulb. If this tab gets mashed down far enough, the socket will stop working even if it’s electrically live. Reach in with a wooden or plastic object and bend that tab up to at least a 15-20 degree angle. This is a far more common problem than you might think. It can cause bulbs to burn out prematurely, but if it’s mashed too far down, it causes them not to work at all.

If the tab is badly discolored, this can also cause problems. It’s probably easier to replace the fixture than to try to fix it. You can try spraying it with some CRC 2-26 and see if that cleans and deoxidizes it enough. It works often enough to be worth trying but it’s not a guarantee. It’s also not a quick fix. Sometimes it works within 30 minutes but sometimes it need 8-24 hours to take effect.

At this point, it’s a good idea to test the socket with a multimeter as well. If you don’t measure voltage, there’s something else going on.

Check for a tripped breaker or GFCI

The third thing to check is to make sure you don’t have any circuit breakers tripped, or any nearby GFCI outlets tripped. If the light happens to be downstream of a GFCI, a tripped GFCI will cut its power. This is unusual, but I’ve seen stranger things than this. Especially in basements.

Check the wiring

Fourth, check the wiring. Pull the fixture down and make sure its wire connections are secure. It shouldn’t be hard to twist two wires together and screw a wire nut down on top of it, but I’ve seen people get it wrong. Yes, I’ve taken a fixture down to find a loose wire nut inside and two wires not connected to anything.

While we’re talking about weird and wacky things, try replacing the wire nuts. Scout’s honor–I’ve had connections come back to life just by putting new wire nuts in. More than one thing has to be wrong for this to fix the problem, but it’s an easy thing to try. If there’s a red or yellow wire nut holding just two wires together, it may be too big. An orange wire nut is often sufficient size for a light fixture.

After I have new, properly sized wire nuts in place, I like to wrap the end with enough electrical tape to go around it twice. This gives some protection against shocks and also makes it much harder for the wire nut to spin off on is own.

Check the light switch

stop bathroom light bulb flickering - proper wire placement
Loop the wire around the screw like this, then tighten the screw. Cut back enough insulation so no insulation touches the screw. This gives a firm, secure, reliable connection.

Finally, check the light switch. Light switches do go bad after a while, and not everyone wires light switches well. Take the light switch out of its box and examine its wire connections. The wire should be completely looped around the screws, not just cinched down under them. If the screws look oxidized at all, that’s a sign the switch has been there a while and could stand a replacement. A new regular duty light switch costs 75 cents and a heavy duty switch costs $1.50 so it’s not the end of the world if you have to replace one.

When you replace or rewire the switch, be sure to strip back enough wire from each connection that you can form a loop of wire into a full letter “c” and cinch it down under the screw without the screw touching any insulation. That gives you a really solid electrical connection. Cover the terminals with a piece of electrical tape after you finish.

If you do all of that and it still doesn’t work, there’s a problem with your wiring. At that point, you need to call an electrician. There’s no shame in that; I’ve done that myself.

But I’d say 90% of the time when your ceiling light fixture doesn’t work, one of my six tricks will fix it. I wish you the best on your project.

One thought on “When a ceiling light fixture doesn’t work

  • October 13, 2016 at 9:53 pm
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    Before pulling the light fixture down, or any of the following steps – turn the breaker for the circuit off (or remove the fuse if the place is that old). Forgot that part. 🙂

    Reply

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