I'm posting again on this as totally baffled now. After all this time there is still no steering wheel controls working, and today plucked up the courage to take the steering wheel off and change the rotary coupler and the actual controls as well. Tried a friends double din radio and separate audio control adapter which work in his car and still nothing.
I just don't know why since the battery was disconnected first time round with everything working it's not now, even with a totally separate working radio set up it doesn't in my car
Any secret reset procedures/fuses/etc... that I could try?