Horn Stopped Working

[Gizmo]

Hi all, as the title says!

One day I went to sound the horn and not a sound was heard. I've checked the horn itself by hooking it up direct to the battery and it's fine, as is the earth wire connecting it to the body. I've tested the relay and that is OK too, but I hear no click when I activate the horn button. This leads me to believe the issue lies in the wiring between the steering wheel and the relay.

Can anyone tell me which wire(s) in the panel under the steering column relate to the horn? I'm loathe to try randomly applying 12V to any of them, as I'm not in the mood for getting an airbag in the face!

Cheers,
Gizmo.

[g8dhe]

The circuit and colours etc are here

The wiring goes via the clock-spring to allow rotation of the steering wheel, it may involve that as well of course see here http://igmaynard.co.uk/bongo/forum/view ... 29#p651229