have you been wheeling??? i had went wheeling when i first got my jeep... shortly afterwards my horn quit working. nothing was wrong with it other than having some mud in it. i took it off, ran a little bit of water, really only a little, then shock the daylights out of it. after shaking it i dumped out what looked like muddy water. i left it dry a little while, put it back on and low and behold it works...

just a thought.

 

And a good thought. However, I've measured the voltage while pressing the horn button and there's no juice in the cable by the horn...