DIY Doctor UK DIY Forums

Hello there

I wanted to install an outside light, hopefully taking feed from the nearby switch for my living room light, which is on the wall directly behind where I want the light to be.

I have a 2 gang switch, each with a Common, L1, and L2 connections. The existing single switch was the same but obviously with only one switch rather than two. The existing switch had a brown wire going to the Common, which I took to be the live feed, then a blue wire going out of the switch from L1. There is also an earth wire going to the metal back box.

The light fitting itself has a connector block inside with an earth wire in the centre, and a brown and blue wire each side. I have tried connecting the light to the switch by fitting the 2 gang switch instead of the single, then using a length of 2 core with earth, connected it to the switch by putting the blue into L1 on the second switch, the brown into the common on the second switch, and a bridge wire across the two common terminals which I thought would provide power. This does not work, but I was wondering if anyone can suggest a way that i could make it function, or even if it is possible without having to try to route another live feed through to the switch.

Any help would be really appreciated.

Hi Daveg,
you are misled by the fact that the w*****r who wired your house didn't mark the blue at sw, as a brown sw. live, or use the proper sw cable which has 2 brown cores in it.
there is no Neutral at a switch so not possible to wire another light from there, sorry, see projects 'wiring an extra light',
regards SPARX

Thanks for the reply! I now can understand how the wiring works, and essentially the wires at the switch are really just the one live wire with a switch in the circuit. Have to see about putting a junction in the circuit somewhere.

Many thanks again for the reply.

what you could do is tap off a socket ,with outside lights they are subjected to all kinds of wind and rain ,if your wiring is a modern type with RCD's you could tap off the ring main using a switched fused spur with a 3 amp fuse ,it would then give you protection by an RCD ,but ensure you use 2.5mm cable to the fused spur then you can use 1.5mm from the fused spur