[rotorwrench]

The original horns are series wound so they can be connected either way for function. The grounding part comes from the light switch group where the wire travels up inside the steering shaft to the horn button. The power side is connected directly to the cut out so it will have full generator output. The horn wire terminals fit into the two brass clips as in the photos of the horn. The photo on post #3 appears to be soldered direct to the clips but that's not the way they were originally done.