DIY Doctor UK DIY Forums

How do I fit a new style switch from this ....


to this ...


I have no idea which wires are which or how to find out! :( (The black/blue wires are at the top on the old style switch)

The yellow one goes in the top terminal

The black and blue go to the bottom left
The two reds go to the bottom right

What really matters here is which core was connected to the 'COMMON' or COM terminal.
From what I can make out the common on the old switch appears to be the middle terminal with the yellow connected to it. That being the case proceed as follows:
Connect yellow to top COM terminal on the new switch
Keep the 2 red wires together and connect them to one of the bottom terminals usually marked L1 or L2, although may labelled 1 way or 2 way. It really does not matter which of the bottom terminals you choose so long as both red wires terminate there.
Keep the black and blue wires together and terminate them in the remaining bottom L1 or L2 terminal.
Please ensure that no bare copper wire is exposed outside of the terminals and that the connections are secure - gently tug the wires to ensure they don't fall out.
Finally, carefully fold the wires into the back box ensuring they don't foul the switch mounting screws and secure the switch to the box.
Hopefully this is sufficient information, but if you're still unsure call a local electrician. It's a very quick fix for a competent electrician.

Thank you - all works great!