DIY: SMG yellow cog, dimmed dash lights, dead radio

Sorry for the really vague thread title but I was trying to use key words for someone searching on google.

I had a really weird issue with the M3 last week and I must admit it took some time to sort it out.

Here were the symptoms

1) Interior lights flash on and off (intermittent)
2)Dimmed dash lights (more frequent)
3) Airbag light on ( more frequent)
4) Radio does not turn on or off with key
5) DSC, Harman Kardon and sport button do not work
6) Yellow SMG cog illuminated, no issues with the gear box
7) Really bad radio signal


I plugged it in using three different diagnostic systems, the first suspected culprit was the GM5 module but this showed no faults, the entire electrical system was clear and all the gearbox showed was a K Bus fault.....

After scanning the engine I was getting an intermittent code ( 81 MFL interface ) scanned the steering wheel on its own and it showed no faults.

Long story short I could find no problem anywhere with the electrics so I decided to replace the clock spring/ slip ring assembly and I'm happy to report that all is well.

I searched the entre web to try and find similar symptoms but to no avail so hopefully this can help someone.