replacing a rose lighting fixture

[cpaton93]

Hay,

I need to replace a lighting fixture as the old one was falling apart. Without thinking about it I disconnected the old one to then realise that the cabling that we have there is 3 normal cables with each having the red, black and earth wires coming out of them. When looked it up I saw that one of the cables, (coming form the switch) normally has 2 red cables to show its a circuit. With out this I don't know where anything goes anymore. How do I work it out pulling apart the ceiling and following the cables.

 

[ban-all-sheds]

When looked it up I saw that one of the cables, (coming form the switch) normally has 2 red cables to show its a circuit.

Normally it doesn't - the use of twin red is unusual - red/black is far more common. The black in that case should be sleeved red, but that's not always done.

How do I work it out pulling apart the ceiling and following the cables.

You'll need to use a multimeter on continuity setting to identify the switch cable.

 

[Scoby_Beasley]

The (switched) black should have a red sleeve around it. You can turn off the power and with a multimeter or similar connect (it) across a red and black using a continuity setting. Then get someone to operate the switch, if the reading jumps from a high reading to a low reading then you've found your switch wire. (operate the switch a few times). If no change move on to the next cable and repeat etc. etc.

EDIT beaten by bas