[Chuck Sea/Tac]

So that diagram wants the horn to be grounded separately from the grd that comes from the horn switch and energizes the relay. That’s hard to do without a separate wire, unless your headlight bar has a good grd. Most don’t. Then, in order to bypass the original “hot” wire that goes through the amp meter and light switch ect, a new hot wire must come from the starter or battery. It seems simpler to just repair the weak connections that are causing the problem.