Switch Wiring Help

[John]

My brother has in his dining area a central light and two wall lights. They were operated from just one two gang wall switch, (i.e not 2 way at opposite ends of the room). He wants to change the rocker switch to a 2 gang dimmer. He asked me to do it for him and I said I could go over tomorrow night. I told him not to touch anything until I got there. He has just rung me and said her indoors wanted it doing tonight so he stareted it!!! He wrote down the connections and then removed the switch, he took out the new switch (2 gang 2 way dimmer) and looked for his drawing. Unable to find it he asked wifey if she had seen the "cash machine slip that was on the sideboard", she replied "I've shredded it, you're not supposed to leave things like that lying around!"

I will go over tomorrow to hopefully sort it but I am not a sparky and usually change my light switches etc in the same 'make a drawing' style as above. In the wall back box he has a T&E and a single core grey sheathed cable. The new switchplate has L1, L2 and C on each switch (obviously). How do I wire it so that one switch operates the wall lights and one operates the central light, everything worked perfectly until he 'forgot' where the wires went, so I don't need to lift floorboards etc to get to the junction boxes etc.

My thoughts are: Red to C (then strapped to other C) Black to L2 (on the same switch as the T&E Red) Grey single to the other L2.

Is this correct? If not could somebody help please, I do not want to spend all night at my brothers listening to SIL saying "Is it done yet?"

Cheers

John

[Chipmunk]

This would *entirely* depend on how the electrician wired it in the first place. Your first stop is to identify the live feed, from your description there is a live feed on one wire and 2 loads. The easiest way is with a non-contact voltage tester, in the absence of this, I would suggest using a strip connector to join 2 of the wires, and cap off the third, then turn on the power. If one of the lights comes on, the 3rd wire is your load wire for the other lights, label itas such. Then swap it with one of the other 2 wires [WITH THE POWER OFF obviously]. If the other set of lights come on, the one you didn't change is the live feed. If they don't, try with the other wire. I hope this makes some kind of sense.

If the lights don't come on, the third wire is your live feed, label it, and you'll have to connect it to each of the other 2 in turn to see which one does which light.

Once you have the 3 wires identified as Feed, Wall, Ceiling...

Hook the Feed to C, and strap to the other C, then feed out of one L2 for one light, and the other L2 for the other light.

HTH, be careful, make sure everything's in good condition, and don't let her shred anything else :-D

[Bob141uk]

You should always write things down on wifey's magazine - these never get thrown away :)

[BigWallop]

You really do need a meter, or at the very least a mains tester screw-driver, for this one. The single core cable may be the supply to the switch, and not the red in the two core cable at all. This really should be checked first to find out for sure. Of course, you could check it by asking SIL to hold it while you turn it on at the fuse box (consumer unit). :-)

But, other than the check for the correct constant feed wire, the rest of your wiring scheme sounds fine.