I posted something about the horn a while ago but never found the problem so here it is again. 1. Has anyone else out there had a horn problem that is conneted to a loose steering post problem? When I bought the truck everything worked. When I replaced the headlight switch I found the bolts were a little loose. Tightened it up and no horn. Loosened it and horn again. 2. When towing I need a secondary ground between the truck and trailer. If I do not connect this secondary ground all turn signal operation functions on the left blinkers. Connect it and all is normal. Now here is the catch if I leave the ground connected to the truck, and remove trailer back up lights work with signals and brakes. I have replaced the factory connectors, its not rube goldberg wiring. It is not the particular trailer tried it on other trailers and it does the same thing. I also conected the trailer to another vehicle and all worked fine. Any new ideas or something junping out at someone that I am missing?

 

The steering column needs to be grounded, for the horn switch. I bet if you rig up a temp ground to the column housing the horn will work. If it does then wire up a nice ground setup.

 

I will give it a try. I discounted column groud because speed control works no problem.