So i took the horn off today as i thought it was broken.....
I hooked my AVO ( Amp/Volt/Ohmeter...) to the switched terminals and when i pushed the switch it showed as 12V....
I HAD previously painted it with hammerite so assumed i have "broke" it then, but i thought i would have a fiddle...
There is a small screw on the back of it....i un-did that and it sprang into life, scaring the hell out of me in the process....
I suspect its to adjust the tone of the horn by screwing it in or out and i think when i painted it i just screwed it all the way in locking the diaphragm down fully....so no tone!!!!
Just thought i would post in case anyone else had seen the issue....
Said screw shown here:
