Mysterious Non-Functioning Wall Lights Wiring - How to Fix?

mrobsessed

Hi All,

When I moved into my house I noticed two connections sticking out of the wall at the level wall lights would be. Both consist of a grey 'ring main type' wire coming out of the wall connected to a brown plastic 4-way junction box of type used for lighting. The wire has solid copper cores coloured red, black and a plain copper one which has had the green/yellow 'earth' sheath added. I've tested the wires and neither seem to have any power in them and there is no switch visible for them either. The walls have been plastered so I can't see where the wire goes from them either, so I'm completely stumped as how to diagnose and fix this problem.

The job looks like a bit like a bodge as the wires emerge from rough holes in the plaster that has not been filled and the junction boxes seem to have been added as a clumsy fix to make exposed wires safe, even though they don't seem to be connected to the power. Needless to say it looks a mess with large junction boxes dangling from wires at eye-level. The house has been rewired in the last 15 years.

If there are viable wires in the wall I'd like to install wall lights and a switch (or individually switched lights), but how do I find out what's going on behind the plaster and how these connectors relate to the rest of my wiring? Can an electrician work this out with wire detecting equipment?

Any help would be appreciated!

DCFC79

Yes i would have thoguht a sparky would be able to do that with whatever gizmo he has, im bet its something he would see often.

societys_child

I'm sure a sparky would soon work it out, but my first thoughts are:

(whatever has been removed could have had integral switches)

1. are you sure they don't become live when the main room light is switched on?
2. could they be wired directly from the consumer unit and been switched off or fuse removed?
3. have any floorboards in the room above been lifted and these wires disconnected from the wiring circuit?

these ideas seem unlikely but . . .

27col

As society says, there are several more tests and investigations to be carried before any conclusion about the wires can be reached. If you are sure that there is no power to the wires then the most likely possibility is that they are controlled by the switch in the room or that they are wired back to the CU and have the breaker or fuse out. But this seems a bit unlikely. Exposing the wiring would be a real last resort. If you cannot sort it yourself then get a sparky in

mrobsessed

I've tested the wire when the main light is on (and a few other nearby lights) and there's still no power. There's nothing on the consumer unit that looks likely as everything is already on.

I do know that a previous resident was profoundly deaf and had a device on the consumer unit that flashed the lights if the doorbell is rung, but that is long since disconnected.

I agree that the next logical step is lifting boards in the room above and seeing if there is anything that looks obvious or just getting a spark in.

Thanks for your help everyone.

DVardysShadow

One last thing to consider before ripping up the floorboards. Possibly they were switched form another switch on the wall plate. Said wallplate switch is now a single and the wire controlling these points is coiled up inside the wall box.

mrobsessed

I've checked that too - there's just the single wire in the wall switch! :mad:

CaptainKidd

It might be worth checking along the skirting board near a socket to see if there is a cable that has been chopped or signs of a small patch of plaster where the cable once came out to a normal plug that would have plugged into the socket, i have seen this several times myself and although not ideal it does get done that way at times by DIYer's

Nilrem

IIRC any fully equipped sparky will probably have a signal generator that can be used to track wiring (from memory it works by turning the wiring into a radio antenna and sending a signal down it that the other half of the equipment tracks*), which is probably the easiest and most reliable way to track the wiring if there are no visible switches.
The down side is it'll probably be reasonable expensive unless the op has a mate who does electrics and has the right gear.

So the other option is, as has been said to look around for any junction boxes, blanking plates or other signs of an old switch having been disconnected - depending on the location of the lights the switches could be in the next room by the door or similar (rather like bathrooms now seem to be required to have the light switch on the "hall" side of the door, some houses have the living room/dining room/kitchen lights on the "wrong" side of a doorway).



*Similar to, but much more reliable and advanced than the "wire" and "pipe" detectors you pick up for a fiver (and seem to mainly pick up plasterboard...).