help needed fitting a new light switch

[fred4789]

hi all,

I'm needing help to wire up a light in my porch. I already have a light fitted at my front door. When i open the single switch i can trace the supply from the consumer unit & the cable from the light at my front door. The single switch has two red wires connected. 1 in the common & 1 in L1. The black & blue wires are together in a terminal block. I have run a cable from where i would like to have the light in my porch & have bought a new double switch (1 for the outside light at my front door & 1 for the new porch light).

What i would like to know is where do you start connecting the wires back up? i now have 3 cables coming in (black,red & earth from consumer unit, red,blue & yellow from the outside light & brown, blue & earth for the new light) the double switch i have bought has common, L1 & L2.

Hope this all makes sense. Any help would be greatly appreciated.

 

[sparkyspike]

Wire in the existing wires to one side of the 2 gang switch, as they were before, using com and L1. Leave all other connections as they were. Wire a short link of brown between the two com terminals. Wire the new brown into the remaining L1, and the new blue into the block with the blue and black. Connect all the earth wires together into the earth terminal. That's just the wiring part of it. Then there's testing and certifying etc etc blah blah... If you're not sure how to do this, then you'll need to get someone in who does.

Incidentally, what does the yellow wire do? Is it a spare, or is it used as an earth, or something else? If it's used as an earth, sleeve it completely in g/y at both ends.

 

[briwire]

Just to add to what sparky said. Regarding the short link between the commons. This is assuming that the live from the consumer unit is the one going to the common, it could have been connected to the L1, both would work. So check which is which. You should have one wire which is permanently live and the other is on ly live with the switch in the ON position. Its the permanent live that the link goes to.

You might also find that the new light is ON with the switch in the wrong position. If so, just move the wire from L1 to L2 instead.

 

[fred4789]

Many thanks for the info guys worked a treat!!!