We've recently fitted a new light fitting into our bedroom - it's on a loop switch, connecting to our back bedroom. There are 3 sets of cables, 1 set has a black and a red, 1 set has a black, red and earth and the last set has a black, red and a bare wire which we assumed was also an earth cable. We used a multimetre to identify the live wire and the switch wire as this wasn't marked. The second set had the live red wire, and we believe the switch wire. We wired everything up - but that's where we hit a problem. The light in our room doesn't turn on with our light switch - the switch in our room isn't doing anything now. But when we flick the switch in the back room, it turns on both the lights in our room and the back room. Clearly we've wired something up wrong - but wecan't find where! Can anyone advise?