2 gang light switch problem & earthing back box query?

[solorize]

Hi,

I currently have a 2 gang dimmer switch, which the left hand switch operates the main ceiling light,
and the right hand switch operates two wall lights.

I decided to unscrew the faceplate to see how the wiring was connected before I bought
a new (non dimming) 2 gang switch.

What I found was...

20201031_112215.png (1.01 MiB) Viewed 1158 times

I have made a note of how everything is connected so when I change the faceplate I know where all the wires go.

But, now I have one problem and a query;

Problem.
The odd thing once I screwed it back onto the wall turned the power on and clicked the dimmer switches was that
the ceiling light came on (when I clicked the left switch), but when I clicked the right hand switch only one of the
the wall lights came on.. I swapped the bulbs over and still only the same one light came on, so I know the bulb
had not blown.

I would have thought that if there was a problem with the right hand dimmer switch that both of the wall lights
would not have come on. F.Y.I, I did not yank the wires when I took the faceplate off.

I have since taken the faceplate off again and reconnected the yellow and red wire which is in the Right hand L1
terminal, just in case it was not making a good contact as the wire was visible as seen in the above image. But
unfortunately that did not help.

Therefore, can anyone shed any light onto why only one of the wall lights is working ?


Query.
As mentioned earlier I will be replacing the existing 2 gang metal dimmer faceplate with a
2 gang flip (non dimmer) switch, and as such I believe there will be no need to earth the plastic face plate.

Currently as seen in the below image, the earths (even though the two wires coming from the cables look blue,
they are a funny kind of dark green if I point a torch light at them), are all connected together in a connector block.

green wires.png (377.29 KiB) Viewed 1158 times

So, when I install the new plastic faceplate, can I keep the earths as is. i.e. keep them connected in the connector
block, or should they be fixed to the metal back box?

The only problem I have is that there is no fixing screw in the back box earth terminal, as can be seen @ top right of the
back box, in the first image posted.


Regards
Mark

[Someone-Else]

If a light does not work, but it did before you pulled out the switch then you have a bad connection to one of the lights.

You should either try pulling each in turn to see does it come out, or re make all the connections. I would look at the red and yellow on the switch on the right (as we look at it)

As you have no back box earth undo the earth from the dimmer switch, undo a back box fixing screw, put the fixing screw through the earth crimp, tighten the fixing screw, but only do this when you change the switch to a plastic one.

[solorize]

Hi,

Thanks for you reply.

I did re-seat the yellow and red wires earlier deeper into the terminal, but that did not help.
So I will have a look tomorrow and see if there are any obvious loose wires elsewhere.

I may just buy an other metal faced switch plate instead of plastic and then I guess I can just
wire the earth back to the rear of the faceplate (as long as it has a connection), so it keeps
the same setup.