Wiring a 2 gang dimmer switch for ceiling and wall lights

7 Nov 2006
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United Kingdom
I have foolishly removed a 2 switch dimmer switch to decorate in my lounge and did not make a note of where the wires went in the switch. I would be grateful of any help to re-wire this.

The 2 switches operate a ceiling light (switch 1) and my wall lights (switch 2). Each switch has a Common, L1 and L2 terminal.

I have 2 cables coming out of the wall:

cable 1 has black, red and earth wire
cable 2 has red, blue, yellow and earth wire
I also have a short piece of red connecting wire

The black and blue wires are connected to each other in a separate block. The two earth wires are connected into the back plate earth terminal. So I have two red and one yellow wire to connect up, plus the short connector wire.

I believe that I had one red wire going in to one common terminal (I believe this would be the permanent live), with the connecting wire joining the two common terminals. Then, one red wire went to L1 on switch 1, and the yellow wire to L1 on switch 2. Does this sound right?

If so, my problem is that I have two red wires, and I don’t know which one goes into the common terminal – will it be the red wire from the cable 1 (no yellow wire) or from cable 2 (with yellow wire)?

All help gratefully received!
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It could be either of them.From how you have described it sounds like the black and blue are neutrals in their own connector.With the power off I would join one of the reds in a connector with the yellow.If when you switch back on one of the lights is on then that red is the live feed.If not swap reds (again with power off) and that should put one light on.Make sure the red you leave out is safe in another connector or wrapped in tape while you test
Big thanks ricicle

Only just got round to trying this after finishing my decorating.

Your suggestion worked brilliantly


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