I'm trying to replace a double light switch in my living room that has two light fittings on the ceiling.

Coming in are 1 live, 1 earth and two other wires (presumablu switch wires).

I'm using a 10amp double 2 way switch and have split the live wire to produce two feeds, which I've connevted to the two com terminals. The two other wires are connected to the two L1 terminals.

All works, except that the secomd light only functiomd when the first light is switched on.

Any advice would be much appreciated!

Thanks for the interest here;s the answers to your questions.

It's new behaviour, I'm just trying to replace an old 70's style switch which was wired as black to com, both red wires to the l2 connections and a "patch cable" going from the first com to the other.

Just one switch used to work both lights.

There are no other switches involved.

The live wire is black and the other two are red with no markings at all.

I've tried every cobination on the switch and can only assume the new switch is the wrong type.

Regards, Mick

Thanks - that makes sense.