[Green Trail]

I am not sure how close this would be to yours, but this is the basic T30 wiring. You may need a steering wheel control connector from CONNECT2 they sell them on ebay to retain the steering wheel controls.

 

[Green Trail]

Thanks , that's literally EXACTLY what I needed... maybe I should have guessed but the ground cable on the harness doesn't do anything, touching it to a metal point has powered it on thanks again

I am struggling to remember if the chassis is earthed when it is screwed on.