light switch replacement, 2 black & 2 red wires

[dgoulston]

Hello All

I have the above light switch currently installed in my new house and it has 2 switches on it of which only 1 does anything.
so I want to replace it with a single switch (with just the Com,L1,L2)

But what wire goes where?


Thanks in advance

Darren.

 

[EFLImpudence]

It can't work properly wired as it is.

What are the two switches supposed to do?

 

[dgoulston]

the right hand button turns the lights on and off

the left hand button does nothing.
It should only be 1 button!

 

[EFLImpudence]

Do you have any lights which don't work ?

 

[dgoulston]

only moved in 4 weeks ago,

yes in the hallway, does not work.

I have replaced the fitting in the hall, have been looking at lots of diagrams tonight.

if I am on the same page as you, do you think the reds should go to coms & blacks to L1's?

 

[EFLImpudence]

One other question first.

Is the light that does work controlled by another switch as well?

 

[dgoulston]

no this is the only switch.

 

[EFLImpudence]

In that case, to get your new switch working -

Looking at your diagram -

Put the bottom row Common and the top row L1 and L2 into the same terminals of the new switch and

put the other wire (bottom row L2) into a separate connector and tuck out of the way.

Discard the blue bit.


I would advise asking an electrician to look at it as you may be able to work the other light but it would not be safe to advise you to put this there and see if it works.

 

[dgoulston]

Thanks a lot, that worked perfect.

there is a switch under the stairs that does nothing so I am hoping that is for the light in the hall.

Thanks again
Darren

 

[dgoulston]

would it be possible to test which cables are which using a multimeter?

Also, would L2 really be needed? as I thought it would be disconnected when the light is turned on as the current would go through Com->L1?

I am new to all this electrics, but am doing a lot of research and trying to learn how it all works before dealing with stuff.

 

[securespark]

Did the fitting in the hall work before you replaced it?

If not, it could be that the vendors removed (eg) a metallic switch and fitted (wrongly) a white one in its place.

Which is the light that does work? Is it the landing?

If the hall light does not work and it is because of this switch, then you'll want to keep it as a 2 gang.

You can do some tests to find out what wire does what.

Using a multimeter on the 230V setting, you could find out which wires are live. Take great care doing this.


Using a multimeter on a continuity setting, you may be able to find out which wires go to another switch (if they do) as long as you can find trhe other switch.

We really need to know what wires go where before we can decide what to do with them.

If the wires you have connected as advised by EFLI are for a two or more way light (ie one controlled by 2 or more switches), then it could be the "redundant" core switches the hall light that is currently not working.

BUT, you need to do some digging to find out more.

 

[dgoulston]

The working lights are in the living room (2 lights)
[light 1 had 2 cables, light 2 had 4 cables] they are both controlled by the 1 switch.

The second switch does not do anything.
The light in the hall (wall light under the stairs) does not work and never did, there is a small rectangle switch 1m from it but was unable to get it open without damaging the wall (inset).

I have a Continuous LIVE wire detection arriving today, so hopefully will be able to use that to trace most of my wires and get a better idea!

I am 100% there is not other switch for these lights as all the other switches in the house work fine (other than one under stairs mentioned above)

 

[ban-all-sheds]

would it be possible to test which cables are which using a multimeter?

Yes. Do you have one and know how to use it?

Also, would L2 really be needed? as I thought it would be disconnected when the light is turned on as the current would go through Com->L1?

Not needed for 1-way switching unless the switch is the wrong way up and can't be rotated through 180°.

Are you sure your drawing is right? I think I can see a diagonal line on the back of the switch which would indicate a different layout of the respective COM/L1/L2s.

I am new to all this electrics, but am doing a lot of research and trying to learn how it all works before dealing with stuff.

Good man.

 

[dgoulston]

Yes. Do you have one and know how to use it?

I know the basics of it and I am a very quick learner.

Are you sure your drawing is right? I think I can see a diagonal line on the back of the switch which would indicate a different layout of the respective COM/L1/L2s.

Yes there is a line as it is a double switch,
line goes

L2 L1 | com
com | L2 L1

 

[securespark]

The switch in the picture looks like an MK Logic, 70's/ 80's model.