Light switch problems

[Wayne39]

Ok here we go,
Not being an expert in electrics, i have a problem with rewiring a light switch, to which i thought would be a easy task, as normally there would only be 2 wires, but this example has 5 wires 2 red, 2 black and an earth.
origanaly some time back i was wondering why my back room, ( a fairly new exstention) which gives excess to the uttility room only had one, one button switch, serving 3 indivisaul lights.
At that time i asked a friend who was a bit more keyed up in electrics, to try and put in a two button switch, in the hope that i would not have to turn all the lights on at any one time.
problem is the double switch only did the same, turning all the lights on.
we had to leave that switch in at that time, but since then blubs have been popping quicker than normal, night-mare.
So in my wisdom earlier today i thought i would put the old switch back in.
Problem is all the extra wires and lack of fuses to try different combinations.
Can any one Help..

 

[andy]

did you not note what went where before removing the old switch? youll need a multimeter to establish what cable does what

 

[Wayne39]

Andy thx for reply, No I did not make a note at the time i thought it would be a quick easy job, how wrong i was.
plus i have not got a reader, i suppose i will have to leave this job to the morning now..

 

[andy]

Andy thx for reply, No I did not make a note at the time i thought it would be a quick easy job, how wrong i was.
plus i have not got a reader, i suppose i will have to leave this job to the morning now..

youll have to go get a meter (cheap £10 will do for the odd job like you)

or call a spark

 

[Gary0]

2 red and 2 black sounds like 2 cables to me. But only 1 earth ?
Someone hasn't sniped another earth wire back so far you can't see it have they ? Or are the 2 earth joined and going down the one green/yellow sleeving ?

The arrangement sounds so unusual I think folk may be reluctant to give advice without being able to see / test.

But if I had to hazard a guess, I'd think maybe someone wired in 2 lights rose to the same switch That may be way off beam, but it could be seen as a 'quick fix' by someone who had 2 switches, and wanted a single switch to control both without exerting to much effort on their part. But seriously, you do need to work out where each is going.

I think, in your shoes, I'd be tempted to rip it all out and do it properly, but that's the type of guy I am. Hate stuff not being standard and easily understandable. If it confuses me, it'll confuse others, so I get it sorted.

 

[Wayne39]

thx For getting back to me you two,
I got my hands on a meter, and it turned out there was only one red live, so the other red i took as the switch live or in this case loop wires, the missing earth was joined with the other earth.
so after buying some extra fuses, i joined the two reds via connecter and sealed with insolating tape.
put the black neutral from the live red in the com of the new one button swich, and the other black in L1.
All lights are now working as the original set up, and the 5 amp main fuse didn't pop.
Every thing seems ok and i am hoping what i have done here is correct?.
Any way thx again for your Help.

 

[securespark]

It is unlikely that the blacks are neutrals.

You say you only have one live. Have you connected the live to the others in turn to see what happens?

It is impossible to say what you have done is right or wrong, but just because it turns the lights on does not mean it is OK.

Can you post pictures?

 

[Gary0]

Ok, judging from what you said , I'd hazard another guess (and stress that's all it is).

Could be that some bright spark has opted to feed the mains in to each switch, and then run cable to the light from there.

If that were so then the way you connected (putting the switch in one line, and connecting the other directly) would work.

Just 2 comments (aside from stressing we can't be 100% sure that's what's happened).

a) If I were you, when possible, I'd replace the existing system with one that is more standard and which I knew for sure was correct.
b) I think, if I wanted to just get it working for now, I'd have put the switch in the live line rather than the neutral (live to light, into the common) purely on the basis that then the live would be removed from the light fitting when the switch was off, rather than the light fitting being live all the time. Might bite you one day.

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Oh, subsquent thought. You could check whether the light is permanently live at the moment as a way of giving further confidence that your understanding of what's wired where, is correct.

(Of course if your meter has resistance check and long leads, you could check that out for sure on the switch to light cable anyway, so long as it was disconnected first.)