In case this helps anyone, the wiring for the lights runs back under the left side of the tank. Easily accessible by removing the side panel, the two tank bolts under the main seat and sliding the tank back.
I had an issue with the main beam and tracked it back to previous dodgy repair with duct tape, which is now properly crimped. Looks like there may be some other bad repairs on the black/white wires (more duct tape), but I’ll do those another time.
