Hi this is my first post.
I own a 2001 Fiat Ducato 2.8 JTD, LHD Motorhome (Dethleffs), 130,000 km on the clock, had it since new.
My horn wasn't working and there was no power to the horn itself. After searching in the engine bay and in the cab and online, I finally located the vehicle fuse box.
In the case of my vehicle, it's under a black plastic cover in the glove compartment. You simply pull it towards you and voila, there are the fuses.
Fuse 12 was blown ........... horn fixed, now I can put the vehicle thru the inspection tomorrow.