Incorrectly Wired Circuit?? Strange Behavior

[loffler]

I have just moved into a house and am changing all the switches and sockets. The lounge has 1 ceiling rose and 2 wall lights with a 2 gang switch. The wall lights don't look original as the cabling is newer then the rest. The house was built in '64 and all the cables are red/black with grey sleeve. The wall lights are brown/blue/earth with white sleeving, so leads me to believe they were added more recently.

The problem i have is that the wall light will not come on independently to the main light. The main light has to be on for the wall lights to come on. I want the wall lights to come on separately.

The switch has 3 wires to it - 1 red (commoned) and 2 black. One of the black wires is in a single core, the other is dual.
The ceiling rose has 4 cables - 3 triple core and 1 dual core All the blacks, reds and earths are commoned apart from the black of the dual core. going into the light are the commoned blacks and the single black.

The switch and the ceiling rose appear to be OK and all I can think of is that there is a junction box somewhere that was not wired correctly when the wall lights were added.

With this set-up, is it possible to have the wall lights come on independently to the main light?

Thanks

 

[securespark]

Have you changed the switch & buggered about with the connection?

 

[loffler]

no, not changing the switch till i know whats going on. The light has always behaved this way.

 

[securespark]

In that case, I would say that either it has been incorrectly wired from the off, or someone has incorrectly refitted a switch.

Does it look like a replaced switch?

You do not specify which terminals the wires are attached to.

 

[loffler]

The switch matches the rest of the house so think its original. The only thing that looks new is the wiring on the wall lights as its newer wire colours.

The single red wire is in common with a jumper to the other common. The black wires are both in the L1 position on each switch.

Pretty sure its not the switch that's at fault but the way the wall lights have been added to the circuit. I was surprised to only find 3 wires for a start - is that normal?

 

[securespark]

3 wires where?

It does sound like a fault other than at the switch position.

Sounds like for whatever reason, the feed to the wall lights has come off the switchwire for the main light.

Or do you need both switches down to have the wall lights on?


Find the junction box where new meets old cable & you will probably crack it.

 

[loffler]

there are only 3 wires going into the switch - a dual core and a single core cable.
the wall lights only switch on when the main light is on - if you switch the main light off, the wall lights switch off too.
Any ideas on where to look for the junction box. Will it be under the floorboards upstairs? Would it be at the wall end or around the ceiling rose?

Thanks

 

[ColJack]

so to re-cap,

at the switch you have:

1x 2 core ( red and black )
1x single core ( black )

no earths on these cables???

At the rose you have:

3x "3 core" by which I presume you mean twin and earth.. ( red, black and earth )
1x 2 core to the switch ( red and black )

the 4 reds together, 3 blacks and one single black from the switch on it's own...

you say the side lights are in the new colours?

then I'd say there is definitely a junction box somewhere..


also sounds like you might have a polarity problem.. if the single black was live then it would switch to the red when the switch was on and that would common to the other switch..

that wouldn't tally up with the wires at the rose though..

 

[casinojoe1]

where does the "single core" terminate? in the ceiling rose or the wall lights?
the reason why i am asking is because we are getting confused with your terminology, 3 core/single core etc. are we talking twin and earth for the 3 core and twin and earth for the single core but with one wire cut back?

time to get the multimeter out...

it appears that the wall lights are in series with the ceiling rose.

 

[loffler]

ColJack, you are absolutely right in your summation. I also think I have a polarity problem and that not all black wires are actually neutral.

by 3 core i mean red, black and earth in grey sleeve.
by 2 core i mean red and black in grey sleeve.
by 1 core i mean black in grey sleeve.

hope this helps

Is my only option to pull up all the floorboards and get to the ceiling rose and junction boxes?

Thanks

 

[securespark]

You need to find the other ends of the cables that terminate at the switch.

 

[SparkyNinja]

Is there any sign of the newer cable at the wall lights, at the ceiling rose?