# light switch / light doesn't always work



## LeaClair (Jul 11, 2009)

One set of our ceiling lights (it has three hanging lights from one fixture similar style to what you see above pool tables for lights) is connected to a wall switch, all installed about 3 years ago. 

There hasn't been any issues until the past month or so. Now we can't turn the light on/off with the switch, it's like the breaker is off and no response but that isn't the case. The bizarre part is there is a wall socket just below the switch and if something is plugged into it, the light switch/light works. The wall socket is one of those child proof ones, so maybe that has something to do with it? 

Any thoughts or suggestions for troubleshooting?


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## Drabdr (Nov 26, 2007)

Hello LeaClair! Welcome to the TSG! We sure are happy that you dropped by!

Ok, a bit of breakdown on your post, here...



LeaClair said:


> One set of our ceiling lights (it has three hanging lights from one fixture similar style to what you see above pool tables for lights) is connected to a wall switch, all installed about 3 years ago.


OK, good enough. Has anything been changed? Have you installed any of the "Energy Saver" bulbs, or are they just regular, ordinary light bulbs?

Is the house brand new, or really old? Reason for question, is that sometimes depending on the age of the house, they are wired differently.



LeaClair said:


> There hasn't been any issues until the past month or so. Now we can't turn the light on/off with the switch, it's like the breaker is off and no response but that isn't the case.


I'm confused. Are you saying you cannot turn the light off, or the light does not come on? Are you trying to turn off/on at the switch that controls the unit at the wall, or the pull-down chain/string? Does the light come on at all?



LeaClair said:


> The bizarre part is there is a wall socket just below the switch and if something is plugged into it, the light switch/light works. The wall socket is one of those child proof ones, so maybe that has something to do with it?


When you say childproof, do you mean it has some of the plastic inserts so the little kiddos don't stick a key or something in it? If you were to remove the inserts and plug a light or something in it, would the light work.

Great first post.:up::up: Just a little more information will help us get on down the path.:up:


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## LeaClair (Jul 11, 2009)

There are the same light bulbs which aren't the energy saver ones. House is built 1979.

I cannot turn the light on, but if I leave the light switch on and unplug something at the socket I can't turn it off. In other words, the light goes out but if I were to plug something back in the socket the light turn on because the switch was on at the time I unplugged the socket last go around. Make any sense?

In this particular socket I don't need to insert the plastic covers because the socket itself is childproof. If you look where the two prongs go you'll see some plastic pieces that slide out of the way when a plug is inserted. 

Thanks for the help.


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## Drabdr (Nov 26, 2007)

This is one of the oddest things I've heard in a while. 

Is your lighting/power circuit 120V?

So everything in this room has been working fine, and then out of the blue, this situation started up? No one changed out any of the plugs, or did any wiring of any kind?

In general, the use of an appliance/fixture at a plug has nothing to do with the operation of other devices on the circuit; other than to add to the total circuit ampacity. The circuits are generally wired in parallel.

Clarification: The wiring at the device is parallel; saying you don't have to have a bulb in or something plugged into a plug for the rest of the circuit to work. The wiring of the branch circuit is in series, going from one point to another. If something is wired wrong at a plug or a switch, it can affect everything downstream of that device.


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## LeaClair (Jul 11, 2009)

Yeah, 120V (it's slightly lower at the fixtures/outlets ~118/119V when checked with a voltmeter). 

Anyway, I going to pull out the switch and outlet and see if I find any wiring issues. I get lazy about doing that so I was just wondering if there's something else. I was all set to replace the switch when I noticed it worked when I had my vacuum plugged in - so it's not just a simple replacing of that switch.


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## Drabdr (Nov 26, 2007)

LeaClair said:


> Yeah, 120V (it's slightly lower at the fixtures/outlets ~118/119V when checked with a voltmeter).
> 
> Anyway, I going to pull out the switch and outlet and see if I find any wiring issues. I get lazy about doing that so I was just wondering if there's something else. I was all set to replace the switch when I noticed it worked when I had my vacuum plugged in - so it's not just a simple replacing of that switch.


If it was working correctly then stopped working, then it's probably not the wiring. If it was wired wrong when replaced, that's an entirely different matter. 

_Posted via Mobile Device_


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## aka Brett (Nov 25, 2008)

This is an odd one.
Being nothing has been changed in the wiring I am going to assume something is loose.
I have seen a couple strange thing happen with loose wires
One the lights got brighter when the toaster was on,yep got brighter instead of dimmer.
I have seen a ceiling light that didnt work proper unless there was a high current draw on one of the receptacles.

I would shut off the main..pull the receptacle out and tighten everything up good,...do the same for the light switch.
If still having problems pull down the lights and check all the wire nuts
If you find any loose,you just as well get the entire house,will only take an hour or two.
Some electricians seem to get everything tight others dont.


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## JohnWill (Oct 19, 2002)

I agree with the previous post. I'd remove the outlet and the light switch first, since the issue sure seems to be in that area. My guess is it should be something pretty obvious...


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## buffoon (Jul 16, 2008)

When you pull the whole lot out make sure the wiring is as follows:

1. Mains live and mains neutral to the wall plug first.
2. If you see that live and neutral go to the light via the wall switch FROM the socket (which I assume they do), make sure that it is the live (not the neutral) going from socket to wall switch to lamp, that is interrupted by the wall switch.
3. The neutral should be joined (uninterrupted) and not pass thru the wall switch. Either way.

If you find any wiring to differ, change it to the above


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## Koot (Nov 25, 2007)

Your problem almost certainly is related to the neutral wire. I strongly suspect your ceiling light only works when a load is plugged in the wall receptacle that provides the necessary return path (neutral) for the problematic ceiling light. This tells me that your light fixture switch [and ultimately the light fixture itself] is fed from this receptacle or the wiring joints in the receptacle's box.

Note: In your case your light fixture is missing the circuit's return path (neutral), but this return path (neutral) is "falsely" created whenever a load device is plugged into the receptacle allowing it to complete the circuit through the load device. If it wasn't for the load device creating this false return path (for the light fixture) the light would not work. Depending on the type of load device plugged into the receptacle the device may have to actually be energized in order to complete the missing neutral path for the light fixture.

Your neutral wiring problem is located either at (1) the receptacle box (which feeds the wall switch circuit for the light fixture) or (2) the switch box that controls the light fixture.

(1) I suspect you will find the problem being a loose/broken neutral wire on the receptacle itself or a bad wirenut joint in the box. (The problem will be located on the downstream side that feeds the ceiling light switch circuit since the receptacle itself works okay.) (2) If the problem is at the switch box you will be looking for a bad neutral wirenut joint since the switch breaks only the hot [120V] wire feed the light fixture.

The neutral wire will have white insulation.

PS (to Brett) - If you ever have a light that gets "brighter" when a load is energized - then you definitely have a high resistance (poor joint) neutral problem somewhere in the light fixture circuit. The poor neutral connection could be anywhere from the light fixture wiring itself or anywhere there is a connection/joint all the way back to the neutral connection at the load center. It's a good idea to make sure all the neutral wire connections are tight in the load center. And ground wire connections too...


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## JohnWill (Oct 19, 2002)

Your correct *Koot*, that's why I suggested taking both of those out and inspecting the wires.


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## Drabdr (Nov 26, 2007)

Hello, Koot! I haven't ever heard of West Plano before! But greetings from a fellow Texan (Arlington). Superb post, BTW.

Man... there is some golden help here. This is a great post for such issues. I really wanted to find if it's possible it was wired wrong from the beginning (3 years ago), or if this problem just started. To everyone's point, I've also seen a whole variety of issues, from poor ground, worn wiring, plugs go bad (not often, but it does happen), and even things going hinky with the fixtures and things plugged into the outlet.

Too, I've seen a myriad of wiring combinations when you have a fan/light combination, and a 3-way/4-way light coming into a 2-4 gang light switch.:up:

If any of the well-stated possibilities that have been suggested by the other posters could be the culprit, I think I would stop using that circuit fairly quickly and figure out what is going on. 

Buffoon, quite a good post. You're a brilliant debater, and quite the Handyman; is there any skill you lack??:up:


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## buffoon (Jul 16, 2008)

Drabdr said:


> ........Buffoon, quite a good post. You're a brilliant debater, and quite the Handyman; is there any skill you lack??:up:


Patience? Yes patience! Especially with wiring. Koot explained it more in detail but I suspected it to be a neutral fault. Down here (especially in the "campo", meaning the sticks) when you buy an older house you often get that problem (and others) as built in standards. Any builder who ever had a cable in his hand calls himself an "especialista" immediately. You know, see one, do one, teach one. 
After lugging a power drill thru the wall wiring the third time in a week (a detector wouldn't show cable channels up since the wall plastering used here confused it to the point of beeping everywhere) I disconnected the mains and then started chipping open the walls to install proper ring mains.
You know, junction box at top and cables either completely horizontal along the ceiling or coming down vertical at right angle to sockets, switches etc and all in plastic channels and then plastering the whole lot up again.Took me ages.
In the course of this I found older cables had been laid every which way the wind blows, usually in snake patterns. AND in many cases just within their own insulation, no channels. 
I wasn't an electrician then and I'm not really one know but I learned a lot.

I also swore a lot.


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## Drabdr (Nov 26, 2007)

buffoon said:


> Patience? Yes patience! Especially with wiring. Koot explained it more in detail but I suspected it to be a neutral fault. Down here (especially in the "campo", meaning the sticks) when you buy an older house you often get that problem (and others) as built in standards. Any builder who ever had a cable in his hand calls himself an "especialista" immediately. You know, see one, do one, teach one.
> After lugging a power drill thru the wall wiring the third time in a week (a detector wouldn't show cable channels up since the wall plastering used here confused it to the point of beeping everywhere) I disconnected the mains and then started chipping open the walls to install proper ring mains.
> You know, junction box at top and cables either completely horizontal along the ceiling or coming down vertical at right angle to sockets, switches etc and all in plastic channels and then plastering the whole lot up again.Took me ages.
> In the course of this I found older cables had been laid every which way the wind blows, usually in snake patterns. AND in many cases just within their own insulation, no channels.
> ...




Yep, the age of the house can suggest a lot; hence why I was interested in the age. Man your project sounded like a nightmare.


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## Ironwood (Jul 18, 2009)

Check for a loose wire. I had a similar problem in my kitchen, I swore alot and called an electrician. He found a loose wire, turns out that if the wire's are pushed into the sockets on the switches and plugs they can come loose over time. My electrician said to always use the screws to attach the wires to avoid this problem.


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## Drabdr (Nov 26, 2007)

Hello Ironwood! Welcome to TSG!



Ironwood said:


> Check for a loose wire. I had a similar problem in my kitchen, I swore alot and called an electrician. He found a loose wire, turns out that if the wire's are pushed into the sockets on the switches and plugs they can come loose over time. My electrician said to always use the screws to attach the wires to avoid this problem.


That is good advice, indeed. It will always make a more sound connection by using the screws. In general, though, the connections on the back are adequate if there is nothing causing vibrations and such; and if the plug is not a high-usage plug. If there is a lot of plugging/unplugging, that movement can eventually work the wires loose. It does not happen often, but has happened. Also, don't try to stick a #12 wire into a hole made for a #14 wire.

While electricians know that putting the wires around the screws are the best, their actions may show different behavior. Saying, an electrician has to get in, wire a house, and get out in a fairly short time frame, to keep their profit adequate. Adding up the # of receptacles in a house, wrapping those wires instead of putting in the back adds a lot of time to a job.

However, your advice is still sound, and is the best way to approach fixing a plug.:up:


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