Wiring 2 gang switch (1 switch is 2 way and the other is 1 way)

[RenoRanes]

Ok so please bare with me…

Front bedroom of my house (1930’s house) has 2 separate lights and 3 switches (2 gang on the wall and a pull string from the ceiling)

The main light in the centre of the bedroom is connected to one of the 2 gang switches and the ceiling pull string, I’m guessing this is supposed to be wired for 2 way however if the pull string is switched off then the wall switch does nothing but when the pull string is switched on then the wall switch can turn the main light on and off. This i’m not too fussed about as we don’t use the ceiling pull string, we currently just leave that on so we can use the wall switch to turn it on and off. The next bit however is what I’m really scratching my head over….

The second light is supposed to be connected to the other switch of the 2 gang however that switch seems to do nothing and now we have replaced the bulb in the secondary light (was blown a long time ago) we have found that the wall switch for the main light is also working the secondary light but alternating on and off, so if the main light is switched on then the secondary is off and if the secondary is on the main is off.

The 2 gang wall switch appears to have been replaced at some point with a more modern switch compared to the rest of the house. I’m guessing when it was replaced it got wired up wrong?

I have attached some photos of how the 2 gang is currently wired. The side with the grey and red wires going to it is the working main light switch but also alternates with the secondary light. The other side with the L1 bridge and the black wire is the one that is supposed to operate the secondary light but currently does nothing.

Any help with what should go where is much appreciated, thanks.

 

[Ragnar_AT]

It‘s definitely wired very wrong at the switch. The one thing I can’t figure out is how the switch with the link wire and the black can do anything at all. The switch connects the COM terminal (unused) to either L1 or L2. L1 and L2 should never be connected straight together but if they weren‘t the secondary light would never be on.

Here‘s what I‘d do: get a proper 2-pole voltage tester and four choc blocks (connectors). Turn off the power, disconnect all wires from the switch and put each in its own choc block. Turn the power back on and measure between each wire and earth which wire gives you a reading of around 230 V. This is the permanent live and needs to go into one COM terminal along with the red jumper wire, the other end of which goes into the other COM terminal. The grey and one of the reds go into the L1 and L2 terminals of one switch, the black into L1 of the other switch. That should make everything work as it’s supposed to.

A multimeter can be used in a pinch if you‘ve got one but is more prone to giving false readings.

 

[RenoRanes]

Thanks for the reply.

So currently there is a red in the COM of the switch that works, would this switch work at all if that wasn’t correct? (I will try and test it like you said but assuming for these questions sakes it is the correct red for COM), a red in L1 and grey in L2 of the same switch, do the red and grey wires in L1 and L2 need to switch places?
The red jumper currently in L1 to L1 needs to move to COM to COM?
The black currently in L2 of the other switch needs to move to L1?

 

[ericmark]

Since not wire in this I would say that switch is just being uses as a junction box. The two way pull switches, at one point were hard to get, so I would think the pull switch is only on/off.

 

[Ragnar_AT]

Without a meter it’s hard to tell whether the two reds can stay or need to switch places. The way you describe it, I think they can stay but the red jumper needs to link the two COMs to make the second light work independently. That wouldn‘t explain why the two-way doesn’t work. You might want to open the other switch too and have a look at the wires.

Trouble is, there‘s two ways of wiring a two-way circuit. One has the permanent live going into the COM of one of the switches, two strappers linking the L1 and L2 terminals of both switches and a switched live from the COM terminal of the other switch to the light.

The other has a permanent live at each switch (L1) and two links L2 - L2 and COM - COM. The switched live to the light is connected to the link between the L2s. Without measuring you can’t easily figure out which one you‘ve got.

 

[RenoRanes]

I have now made the changes you suggested, moved the jumper to connect both COMs, switched the grey & red around and moved the black to L1. Both lights now work independently of each other on their own switch, the two way still doesn’t work but this really doesn’t bother me, I have no intention of using it, I’ve just shortened the pull string to about an inch long so it’s pull-able if absolutely need be for any reason but otherwise it’s out of sight, out of mind.

Thanks again for all your help