Chasing down electrickery gremlins

Hi guys, got an electrical issue I'm hoping can be resolved. The SRS light started coming on then the horn and the stereo controls stopped working. I've checked the fuse, good. Could this be a dodgy earth issue or might it be a common fault? Cheers!

Hi, it seems very like the rotary coupler in the steering wheel cos the SRS, horns and radio controlls are all through it

Thanks for that. I have a Haynes book of lies and inadequate photography which has no help on this. Tinterweb has em for sale. Any advice on fault finding before replacement?

The rotary coupler is not easy to be diagnosed, eventually unplug both sides of it and make continuity tests across plugs in the same pins but be aware that they have shorting clips within on the airbag circuit also disconnect the battery 10 minutes before you start playing there

download this http://www.green-oval.com/data/lr/rave01.iso for clear diagrams and connector views (patience cos it's large)

Again, many thanks. Have located a replacement for a tenner. So shall dispense with testing. Says in the book of lies and inadequate photography that steering wheel retaining nut needs to be discarded and replaced. Any idea why this might be the case?

maybe they insist on this cos it's a self locking nut which is not self locking anymore after it was once removed, might not be a bad ideea to put a new one M12 nyloc p/n DBP3067L i'd replace it on mine if i was you or at least use some thread locker there.