Replacing older light switches

ashrobbo · 12 Mar 2013 at 06:50

Hi All

Our 80s build still has its original light switches. So I'm attempting to replace them.

I bought some 1 gang 2 way and 2 gang 2 way light switches.

Started on the kitchen which is a single switch controlling one light but I'm stuck

Old switch had 2 red wires into 'P' ( there's 2 holes) and neutral into the bottom. New switch has COM L1 and L2.

I tried to copy the setup on the new switch, and also tried every possible combination but it either

A) turns on off kitchen light ok but then living room light wont turn on
B) kitchen light wont turn on but living room is ok
C) kitchen light turns on, but this turns off living room light and visa verse

I have noticed there is a spare brown tucked away at the back, is this right?

I was just expecting 2 cables so a bit confused when I found 3 (4 with above)

How do I wire this thing?

Pics attached

horrendous aren't they?!

I am replacing with brushed metal one so I am connecting the earth

Magic_x_uk · 12 Mar 2013 at 07:15

have you tried keeping the black on COM, and connecting both red's together and putting them in either L1 or L2?

I would have thought by what you are saying is that one of the red's is a constant feed to the lounge light.

Yes you are correct in connecting the earth. (To the back box as well as the front plate. NOT just the back box and therefore thinking the screw will earth the two)

Nightglow · 12 Mar 2013 at 07:21

I always find this type of wiring infuriating, got it here in my place where they have pinched a live to feed another light elsewhere.

It's just a 1way 1gang switch, so the two reds go to together in Common on new switch & black to L1.

The spare BLACK wire isn't used, they have just used it's adjoining red wire as a means to provide a live elsewhere for another light.
Good to see you earthing the box.

ashrobbo · 12 Mar 2013 at 09:22

Just to be sure, i'm using the same back box (which is plastic) so im just earting the metal switch, is this ok?

Nightglow · 12 Mar 2013 at 09:26

Yes.

Got it working then? :eek:

ashrobbo · 12 Mar 2013 at 14:14

Aha all working now

Thanks NightGlow. May be re opening this thread when I try the two way switches

Nightglow · 12 Mar 2013 at 14:18

ashrobbo said:
Aha all working now

Thanks NightGlow. May be re opening this thread when I try the two way switches

Glad your have it sorted.

C.R.A.Z.Y · 12 Mar 2013 at 17:14

Yeah it's a very mickey mouse and unprofessional way of doing things, decent sparks will simply use the 3-plate ceiling rose system and loop from that.
They have obtained a constant live from the switch to supply another load but they still need a neutral so really they should be obtaining the constant live from where this neutral comes!
Also the black cable should have some RED/BROWN sleeving on or at the very least electrical tape to indicate it's a switch live and not a neutral.

Below is a good diagram of the proper way of doing it (3-plate)

*Edit*
They have however forgotten to show the CPC/Earth going to the switches which is a MUST even if you're using double insulated (plastic) switches as future users may want to change to metal ones
Also whenever terminating cables ALWAYS double over connections.