Upstairs Lighting Circuit Nightmare!!

[Adam W]

So where has the original feed gone then?

That's what I was wondering. Presumably the cable didn't just fall out of the wall, so is probably still there somewhere waiting to be discovered when it's least expected.
Are you sure it's even isolated?

 

[Hiddo]

I removed the part of it the was connected to the CU. I traced every section of the circuit in the loft undid everything and put it back together again knowing where every wire came from and went to. The feed had disappeared (or been cut before I got there).

 

[telectrix]

cherchez le DIY cordless drill