Help Please. Dimmer.

[OscarOne]

Morning all. Hopefully a quick resolution incoming…

I’m fitting a dimmer in the bedroom! Stupidly I forgot to take a picture of the previous switch before removal, however, there were two brown wires wrapped together and a single live wire.

I copied what was the wiring from the previous switch and the dimmer didn’t work. That said, on removal of the new dimmer to check, the two wrapped browns have somewhere come apart and now I have three single browns. One is LIVE, the other two are not.

Can someone help with the wiring? What goes in the com, what goes in either L1 or L2. I can get the dimmer to work now, ‍ (I wrapped the two non lives) however the SECOND bedroom light only works now when the MASTER (new) bedroom switch is on. ‍

Somethings wrong somewhere.

Attached is a pic of the dimmer and the wiring from the back plate.

Thanks.

 

[pete01]

2 wires in wavey line (common) 1 wire in L1, if you don't have any testers swap them around until it works properly, turn the power off first, obviously.

 

[ericmark]

Three wires and two terminals so we can write a truth table, we know one wire live feed to other bedroom, one is live feed to bedroom switch is in, and one is feed in.

So feed in needs to go with feed out to other bedroom, and the bedroom with switch in goes to a terminal on its own.

No problem with any combination, so trial and error works.

 

[huggybear]

Hi OscarOne

Once you've got it sorted out you will also need to connect the earth wires to the face of the switch as it is metal.

Unscrew the three earth wires (keeping them together) in the backbox and connect them to the connection on the switch OR get a new wire with earth sleeving and connect it between the backbox and switch.

Regards,
Huggybear.

 

[Harry Bloomfield]

Three wires and two terminals so we can write a truth table, we know one wire live feed to other bedroom, one is live feed to bedroom switch is in, and one is feed in.

Start by marking your three browns, 1, 2, and 3. Mark the one you know to be live #1, fit that in the 'com' terminal, then try the #2, and #3 in the 'com' terminal along with wire #1, to see what works.

 

[OscarOne]

Hey everyone!

I’m going through all the replies now and are going to work on it shortly. I’ll come back with an update shortly. Thanks everyone!

 

[OscarOne]

To everyone, thank you so much for the very kind replies. Everything is now working as it should, the dimmer in the master is switching on and off perfectly, and no longer affecting the light in the second bedroom.

Thanks again to everyone, and if I may just say a “special” thank you to @huggybear for the advise about the Earth. I appreciate that.

Here are pics from the rear of the finished project incase anyone else has the same issue and runs a search.

All sorted.