2 Way Light Switch - Old to New wiring help

karatekid · May 22, 2024

Hi All

I am trying to replace a 2 way light switch. The photo on the left is of the current light switch and the wiring. New switches look different and I don’t want to guess which wire goes where.

Wondering if you can help? I would assume that COM (left with the red wire) should go to COM1 / COM (right with the Black wire should go to COM2 / 1 WAY (Left with the black wire) should go to L11 / 1 WAY (left with the red wire) should go into L21 and 2 WAY (right with the black wire) should go into L22?

Your help would be greatly appreciated.

[ElectriciansForums.net] 2 Way Light Switch - Old to New wiring help

Yellowhammer · May 22, 2024

1 way switch has the red in COM1 and the black in L11
2 way has the existing common black in COM2, red 1 way in L11 and black 2 way in L22.

Point I would note however is the red conductor on the 2 way looks to have some damage to it/the insulation. I would hazard a guess this is from being trapped when screwed back. I think it would be worth looking at making sure that, at a minimum this is suitably insulated before screwing everything back, and checking the length of the 3.5 screws to make sure they aren't pinching against the back of the box when screwed back.

karatekid · May 22, 2024

Hi, no its not damaged. Its a black mark which rubs off. I checked it. I have also checked all wires and they are secure.

Are you able to assist with the original question please?

littlespark · May 22, 2024

yes. i think youre right...

The new switch is tricky as the one on the right is now upside down compared with the old switch.

Make sure you earth the switchplate though.... its got an earth terminal, so it needs to be used.

Yellowhammer · May 22, 2024

karatekid said:
Hi, no its not damaged. Its a black mark which rubs off. I checked it. I have also checked all wires and they are secure.

Are you able to assist with the original question please?

I thought I had in the first part of my reply! (I believe what you said yourself is also correct)