(UK) What's wrong with my lighting circuit?

[Michael Hendry]

Hello all,
I recently redecorated my living room which meant stripping off the wallpaper. While doing so, some moisture got into the living room light switch (it's a 2-way). I took off the switch plate to dry it out but noticed a wire seemed to be unconnected. I'm assuming this black wire slipped out while I manipulated the switch around. I dried out the wiring and connected the loose wire to the black wires in the terminal block but there is now a problem with the rest of the circuit and I am not confident leaving it the way it is. Basically, what happens is that the 2-way switch works perfectly as before, but all the upstairs lights will not work unless this living room light is on. I am assuming the fuse box (old plug in style) runs to the kitchen, then the first of the 2-ways in the living room, then to the switch in question. After that, I think the loop must run upstairs. All the downstairs lights are fine, it's just the upstairs lights that will not work unless the living room light is on. It doesn't matter if the kitchen light is on or off, only the living room light. My understanding is that the lighting circuit is a sort of daisy chain, so it would appear there is a problem between the last downstairs point in the loop and the first upstairs point?
Any advice would be most welcome, thank you!
Mike

 

[SJD]

Perhaps the black wire you connected into the chock block connector should be instead connected somewhere else? Just because it is black does not mean it is a N, nowadays it would have brown (or red) sleeving to indicate being used as a L, but often that was not done.

It looks like you've moved what is the feed to upstairs from being connected to permanent live, to lounge switched live. Moving one of the black wires will likely fix it, and hopefully you can remember which of the 3 black wires it was!

 

[Wilko]

Hi - ah now you‘ve a first hand demonstration of the power of taking a pic of the existing wiring. I still do this myself as it can save time at the end of the day .

It does sound like the permanent L is no longer going upstairs. But if the downstairs lights can energise upstairs lights I’m thinking more than just one black conductor has moved.

 

[Lucien Nunes]

The fact that all the lights work with the blacks connected together, suggests that none of them is a switched line otherwise either a light wouldn't work or the MCB would trip when a switch was turned on.

I think two red wires have been interchanged - the incoming PL and the SL to the living room light. Most likely, the red in the switch common is actually the incoming L and the three reds in the choc block are the far switch common, the living room light and the loop out.

 

[littlespark]

I’m in Aberdeen tonight if you get stuck.
Just don’t swap too many cables about.

 

[Michael Hendry]

I’m in Aberdeen tonight if you get stuck.
Just don’t swap too many cables about.

Hey there, so sorry I have been out all day and just seen this.
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The fact that all the lights work with the blacks connected together, suggests that none of them is a switched line otherwise either a light wouldn't work or the MCB would trip when a switch was turned on.

I think two red wires have been interchanged - the incoming PL and the SL to the living room light. Most likely, the red in the switch common is actually the incoming L and the three reds in the choc block are the far switch common, the living room light and the loop out.

Thanks very much for the advice LN, I will check this out when I have the chance.

 

[littlespark]

im in Aberdeen for a couple of days. brought my daughter up to uni, and her friends parents have bought a flat. Im putting in smoke detectors and a new consumer unit. gonna be a long day tomorrow

 

[Michael Hendry]

im in Aberdeen for a couple of days. brought my daughter up to uni, and her friends parents have bought a flat. Im putting in smoke detectors and a new consumer unit. gonna be a long day tomorrow

Hello again, thanks for getting back. Sounds like a busy day for you indeed.. I'm actually in Peterhead which is about an hour up the road, so a bit much to ask you to have a look, just while you're up here! Let me know if you've any free time and I will PM you.

 

[littlespark]

sorry, mate... i'm not driving another hour... took me 4 to get here!
I think Lucian has it sussed,,, the reds have got mixed up so the switch is turning the whole upstairs on and off

 

[Michael Hendry]

sorry, mate... i'm not driving another hour... took me 4 to get here!
I think Lucian has it sussed,,, the reds have got mixed up so the switch is turning the whole upstairs on and off

Yeah, a fair trek from where you started off! Thanks to you all, I will check it out tomorrow evening