Outside light, 2 gang switch, Help! Ask questions and find answers to many subjects relating to electrics and electrical work

[daveg]

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.

[sparx]

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

[daveg]

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.

[sparks]

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