I have access to wiring diagrams, but I think there is too much risk using these factory-installed wires - I'll do it the simple way in which you've done. I did think of earthing those yellows at cavities 2 & 4 to earth - the chance are it'd work, but on the other hand it could cause me a load of grief!
If I get a chance, I will have a look at the diagrams early this week.
I would only use a multimeter on the rotary coupler to check continuity of the pins - doing any tests down those wires not knowing where they terminate etc would be a recipe for disaster.
Thanks for your input Alan
