Light switches help!

[Ace Modder]

Hi.

I have had my hallway decorated and during the process the light switches were left disconnected, well they were connected but as the walls were replastered there was hanging and some of the wires have come out.

I have a 3 gang switch downstairs which is:

Switch 1 = Porch
Switch 2 = Downstairs hall light
Switch 3 = upstairs hall light

Then I have a single switch upstairs on the wall that is for upstairs hall light

The problem I have is the switch 3 for the upstairs hall light is not working at all, I can switch the light off/on with the other single upstairs located switch, but the 3 gang switch downstairs for it doesnt work.

What have I done wrong with the wiring? Any ideas?

This switch works fine for the upstairs light.

This below image of the switch is the downstairs switch which is NOT working for the upstairs light, the switch that isnt working is the right most switch of the 3 the one with the yellow/blue and red cables. Any ideas what is wired up wrong? I don't know which switch and which wires are wrongly wired up.

 

[BUDFORCE]

Do you have a multimeter?

 

[Ace Modder]

I do, but no idea how to use it

 

[Adam_151]

First of all, you must earth the switch plates, I assume there is an earth to the backbox?

Assume the terminals are labeled com, L1, and L2 with com at the point of the isococles triangle?

In which case standard 2way conversion method, the cable with red/yellow/blue is connected like to like between the upstairs switch and the downstairs i.e. com to com, L1 to L1 and L2 to L2*. At the upstairs the red and black are in with L1 and L2.(convention is red to L1 black L2, but doesn't really matter, as long as you remember which way it is**) At the downstairs switch the jumper to the commons[which it looks like you have? - cant see picture clearly] of the other switches is in with whatever colour has the red in upstairs (usually L1**)

*Its most common to Use red as common, yellow as L1 and blue as L2. Some people use Yellow as common. No one ever uses blue as common (you can if you want to be different!)

All the wires going to switch terminals are Line conductors, so should have a little bit of red sleeving or tape on to ID them