Build Day 198.....Horn

I'm not able to finish the charge cooler at the moment, as I'm awaiting parts to be delivered.
In the meantime, I've been looking at the horn. Fitting the horn itself (I'm just using the old unit from the Sierra) and wiring it into the loom was quick very straight forward. However, the complex part was to modify the rover steering column parts that allow for a horn button in the middle of the steering wheel. Because I'm using a different wheel, it all didn't fit together. After a lot of messing about, this is just about complete.

However, it seems that the horn doesn't want to work :(

I know the horn itself works. I also know that all the wiring I have done today is correct and working. The fault seems to be in either the original rover loom, or in other wiring I did at an earlier stage. I'll have to trace this further.