conecting a light to an exising 2 gang switch

[john025]

Hi
i need to connect a new light to a 2 gang switch. only one switch is connected at the moment in the following manner. (2.5 Flat) triple earthed cable, this powers a light in the utility room.
earth to earth (connector back of box)
red to C
blue to L1
Yellow to L2

the light i want to connect is an outside light (no PIR)
the new cable is 1.5 twin earth
i take it that i should do the following to connect the new light to the other switch
sleeve N and connect to other N on box
run a piece of brown/red from existing red C across to C on the other switch.

my question then is which does brown on the new cable connect to?
which does blue then connect to?

 

[mikhailfaradayski]

...sleeve N and connect to other N on box

not sure what that means.

The utility light that you mention, how many switches does it have controlling it?

As you describe the current wiring, i think you have no neutral present at the light switch.

 

[john025]

the utility light is wired into a 2 gang box but only wired to one rocker switch
just double checked it, it is as follows
earth to back box
red to comm
blue to L1
yellow to L2

the other switch has nothing wired in to comm, L1 or L2
this is an existing switch that had been installed prior to my buying the house.
if this isn't correct then i need to get it sorted before proceeding to do anything else.

 

[mikhailfaradayski]

The utility light that you mention, how many switches does it have controlling it?

 

[john025]

one

 

[mikhailfaradayski]

ok, at the light fitting, can you see what colours/how connected?

(photo might be easier)

 

[john025]

sorry but i should have mentiond the switch also powers the garage light.
it runs from a junction box in the garage to the switch using triple earth as described. the junction box then has a cable for the garage light (twin earth) and a cable for the utility light again twin earth.
i will photograph the wiring connetions in the switch tommorrow and post it in a reply.