4 black 4 red wires 1 earth

[Flumpy]

Hi. I’m changing a ceiling light that is part of a 3 way switch. Stupidly I didn’t take a photo, I just can’t get it working properly. I’ve put the reds in a box out the way and the earth where that should go, but the 4 black wires are confusing me. Any help would be great

 

[UNG]

One of the black cables is your switch wire which should have been identified with a red sleeve or red tape

If none of the black cables are marked you will need a multimeter or continuity tester to identify the switch wire

The reds should be connected in the 3 middle terminals of the ceiling rose

 

[Flumpy]

Excellent thanks I’ve just bought a tester so I’ll find out the live. I take it the other 3 go in with the blue wire

 

[UNG]

Excellent thanks I’ve just bought a tester so I’ll find out the live. I take it the other 3 go in with the blue wire

If you turn the light switch on with your tester set to continuity you should see a low resistance reading and / or the continuity buzzer sounding between the reds and one of the black cables to confirm it is the switch wire turn the switch off and test again unless you have a helper who can operate the switch while you are testing, that black connects to the terminal with the brown wire and as you say the other 3 blacks connect to the terminal with the blue wire

 

[Flumpy]

Thank you so much for your help that has worked just fine. The tester is a god send. I’m learning gradually. Thanks again

 

[UNG]

Thank you so much for your help that has worked just fine. The tester is a god send. I’m learning gradually. Thanks again

It's quite simple when you know how to do it although the time saver is marking the wires as you disconnect