Replaced the horns on my bike yesterday. Not a big deal but an interesting ( perhaps ) because I wasted a lot of time trying to trace the fault in the wiring before I realised both horns had failed.
I was fooled because the horn worked fine up until the day when I had to ride for about four hours in the rain. I therefore assumed that water had got into the sytem somewhere. I worked right through the wiring for the horns before finally testing the horns themselves. As there are two horns, and as it had been working before the rain, I thought it unlikely that they would both fail simultaneously.
However, what I hadn’t taken into account is that the horns are wired in parallel, so that if/when one fails the other will still work. So what happened here was that I had been running with just one working horn since I bought the bike.
Much louder now that I have two instead of one.