Please help a dumbass

[ban-all-sheds]

If you only had 2 red & 2 black at the original light then the loop wasn't running through there, or if it was that's where it finished. For it to have carried on there would have had to be 3 twin & earth cables, obviously.

The problem will lie at the junction box.

 

[ColJack]

do the other lights switch on when the light you've changed is switched on?

it may be that they are linked on the back of the switch and that the black wire from the switch was being used as the live wire and the red as the switched live..

as we've already said, post us a photo of the light fitting and it's connections and do us a photo of the back of the switch..

it's much easier to diagnose from a picture than a dozen possibly misleading words..

 

[JSR]

Ok perfect - i'll get some taken tonight and post them on here!