1 gang to 2 gang

[darkblue]

changing a 1 gang 2way to a 2 gang 1 switch 2 way (ceiling light) 1 switch 1 way downlighters.2 cables on existing switch 1 with black L2, Red L1. 1 With Red Com,Yellow L1,Blue L2.How do i connect up the 2nd switch

[Adam_151]

transfer wireing from existing switch to one half of new switch, wire your new light (??) to the other half of the switch (you can other take the feed through the switch, or loop in somewhere and drop a switch branch to the switch)

Not sure I really udnerstand the question tbh...

[darkblue]

I've done that and ceiling light is working as normal. I'm left with the cable going to the transformer 2 wires brown & blue and an empty switch. what to do now.

[Adam_151]

Well you need a feed that you can switch onto the transformer cable, you can most likely bring switched live from one of the terminals of the other switch to common, connect the live to the transformer to L1, the neutral from the transformer is going to be the sticking point, its unlikely that you have a neutral at the switch (do you have some blue or black wires in a choc block behing the switch?)

Best way would be to drop down another T&E that picks up power from a JB on the lighting circuit