GU Steering wheel audio controls install

[Cremulator]

Ok, thanks. Why do you splice the audio yellow wire to the cruise control green wire?
Also, on the radio side of the loom you made, is that an earth open tag that needs to be connected to ground somewhere?

From memory I spliced the audio yellow wire to the cruise control green wire as I thought the green was the cruise control earth wire, but I have a feeling that someone else has spliced it to the cruise yellow wire and it works the same, but worth testing yourself.

Yes, that's is an earth wire on the radio side of the loom with the ring terminal that needs to be connected to an earth point.