I've attached the generator/regulator wiring diagram and schematic from the 1956 Ford Workshop Manual along with the colored diagram from ClassicsWiring. As Paul mentioned above, they both show two yellow wires, one from the regulator B terminal to the horn relay, and one to the dash and then on to the battery. A black wire with a white tracer runs from the regulator F terminal to the field terminal on the generator. Two yellow wires with black tracers run from the A terminal on the regulator. One goes to the generator light on the dash and the other goes to the armature terminal on the generator.
I've used the ClassicWiring diagram to sort out wiring problems on my 56 and I was impressed with all the circuits in it that weren't even shown in the WSM, however I did find one minor glitch in the CW drawing. I couldn't find a symbol for a yellow wire with a black tracer. I'll email them and see if I missed it, or they did.
Jack, I also added the horn relay wiring from the WSM and the CW already has it. They match so I'm not sure what caused your horn problem, but those types of things become easier to solve with the internal circuits shown on the CW diagram.
Don