The horn works as a set of switches and spring. When you put power to it a coil is magnetized and pulls a shaft to one side. That opens a set of contacts and the diaphragm acts like a spring and returns to it's original place which closes the contacts again. Repeat a bunch of times and you get sound out of the horn. If the contact is bent or just warped from over heating it will just go to the one side and say there. It chirps so the coil is good. You can hear it so the diaphragm is good. Open it up and clean the points. Might just save it. Just what pickuptruck did to save his. 6 volt or 12 volt they work the same. I would use a relay on that horn to reduce the current at the horn switch on the steering wheel. That will let that connection last longer. Try it you arent out much and just might have the joy of "restoring" a part of your truck. Fun stuff.
