Lighting problem / Electrics expert required!

[StuartGSXR]

Ok, well the signalling fuse was fine but I changed it anyway, still no change. As the tail lights light up ok when the ignition is switched to park lights I did not think it would be the problem... although even with that fuse out the park lights work. If the only thing they need to work is the fuse and ignition being on it should be simple, but then the brake light is not working either.

I am thinking its got to be one thing that is causing all these issues. as my bike is a daily rider, its not like its stuff that could have built up over time. It had its MOT a couple of weeks ago so the horn and rear lights would have definitely been working then. I am still thinking that it is relay related although I do not get how it could be effecting the rear lights or the horn unless there is some sort of rerturn feed via one of the relays.

I have spoken to an electrics guy at work and he does not think the relays are at fault as they only control the headlights. With the list of things not working he thinks it is more likely there is a major wire in the loom somewhere that supplies all the things that are not working which is not connecting as it should.
This is fun