The factory committed an error in the 1968-1969 XLH Wiring Diagram.
We don't normally "correct" factory documentation. However, following wiring diagrams is difficult enough - so we did it in a way that preserves the factory documentation but also helps the restorer do it right. We hope you agree. Check out: 1968-1969 XLH Wiring Diagram
Thanks to Perry Ruiter and his eagle eyes.