Hi New to the site.
This is great information as I have exactly the same problem with my 2005 X-Type 2.2d Estate. Just for clarity, please could you confirm which wires are to be joined in the diagram of the Gem?
SW switch input = Horn SW Switch (IP6 Pin20 BG)
and horn output wires = Horn Relay (IP5 Pin14 B)
Are both in the GEM as I am not sure why the backup sounder is shown?
Many thanks in anticipation