Alfa 75 Horn wiring

[WhiteAlfaGTV6]

Hi, Can anyone describe how the wire goes from the horn switch to the relay and how I can access it. Remove steering column shroud??? I have a black wire at the steering wheel heading down the steering column somewhere. I have a mauve/black wire going from the relay but there is an open circuit in between. In a 105 they go down the inside of the steering shaft but it appears different in a 75. Anyone with some experience with these.