There are times when it makes more sense to just remove the wiring from the bike, and put it on the bench for inspection/testing/repair. I realize that, for some, this will be daunting...spaghetti to be put back in the box:43: It really isn't as bad as all that. In fact, the wiring on these bikes is pretty basic & straightforward. No joke, you simply work on one lead at a time. Once the harness is unwrapped, it's easy to trace each lead end-to-end. If something has been cut, altered, or is broken, it'll be readily apparent. If you find a break, using a continuity tester, it'll be a lot easier to deal with on the bench instead of in the bike. And you pretty well need to have the wiring on the bench to execute proper repairs, a.k.a. soldering & shrink tubing.
Look for rub-through spots on the insulation, little peeks of copper strands, thin spots (which can indicate internal breaks) and rodent damage, as part of the process. I'd suggest replacing the sheathing that protects the exposed portion of the wire harness, between the frame & HL assembly. The original material will be crunchy and that creates stress risers...tough on wires. Some new, pliable, sheathing and maybe a new rubber grommet are good investments.