I replaced the bathroom ceiling light recently but since I did this, it is permanently switched on and if you flick the switch to turn it off, it trips the upstairs lighting trip switch at the fuse box.

I thought that connecting live to live, neutral to neutral and earth to earth would give the desired behaviour but not the case. I took a photo of how it was wired up before I even touched anything (below).

enter image description here

As you can see there are three live/neutral and earth wires coming from the ceiling. I wasn't too sure what the purpose of the white terminal block was which seems to link up two neutrals from the ceiling which I would have thought would just do the same as putting all three into the brown terminal block.

Anyway, it is an incredibly tight space to work with the amount of cables here but I am assuming I would need to rewire it up exactly as it was before as per the photo? I'd be interested to know why it needs to be like so (I tried searching online but there are so many various scenarios I thought it would be easier to just explain my case with picture here).

There is just one light switch for this bathroom light.

  • 1
    Hint: look up "switch loop" Oct 1, 2017 at 12:11
  • does it blow the CB if there's no bulb when switched?
    – dandavis
    Oct 1, 2017 at 22:26

1 Answer 1


Well you can see how they set this up. The old lamp goes into the back side of terminals 2 and 4, and that's it, done. I have no idea what would possess you to mess with any other wires, in the photo it's right.

Left to right the four terminals are

  • always-hot (from supply, to other load, and to switch)
  • neutral (from supply, to other load) and on the other side to lamp.
  • earth (from supply, to other load, to switch, and to rose)
  • switched-hot (from switch) and on the other side to lamp.

Put it back and you should be fine.

The odd little white splice simply appears to be because the black wire is too short.

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