2-way 2-gang problem

[beakydave]

Hopefully someone can help diagnose my problem. I have single-gang 2-way switch in kitchen and a 2-gang 2-way switch at the other kitchen door, that switch also feeding an outside light. I've bought a new 2-gang but seem to have wired it incorrectly (tried to replicate original, bearing in mind that L1, L2 and L3 are laid out differently on the new one). My difficulty is that whoever wired previously did not sleeve the wires, and all I have are blacks and reds.

Outside light is fine. Problem is that I now have to have one of the two kitchen light switches in the 'on' position to have the other one work. If either of the switches is on the 'off' position, the other one will not work. Not that it will mean much, but the wires I have are 2 reds and 2 blacks with the commons (L3) being connected by short red. One red goes to L3 on the bottom, the other to L2. The two blacks to L1 and L2 on the top. This configuration doesn't seem to agree with any wiring diagrams, but it is the way the original was wired - honest!

 

[securespark]

If you've wired it as it was before, it should work.

If it does not work then either:

it did not work before you changed the switch

or

you have wired it incorrectly.

Can you post a piccy?

Have you altered the wiring in the switch on the other side of the kitchen?

Chances are if you have not, then one PAIR of red/blacks is the live and switch for the outside light, while the other are the strappers for the two way switching for the kitchen.

You need to identify (using safe isolation) the live feed. This goes to common of one switch, with the link across to the other common.

Then the switchwire of the outside light goes to the terminal of the switch you want to use for the O/S light that is connected to common when the rocker is in the down position.

The strappers then go one to each of the remaining terminals on the switch adjacent.

 

[nozspark]

Swap L1 & L3

On your old switch you had a C, L1 & L2.. this is now L1, L2 & L3 respectively on the new switch

 

[ban-all-sheds]

And get a multimeter.

Absolutely essential tool - as vital as a screwdriver, and with one you could have identified the wires and confirmed which switch terminal was which.

 

[beakydave]

Swap L1 & L3

On your old switch you had a C, L1 & L2.. this is now L1, L2 & L3 respectively on the new switch

Thanks - I feel a proper clot

I had assumed that L1 and L2 would be the same as the old switch and it was simply C and L3 that had swapped. All I had to do was look more closely at the back and would have seen the dividing line between the two switches and been able to identify the terminals.

 

[nozspark]

No problem, glad you've sorted it!