If you have a stock harness that has not been cut up, it is fairly straightforward. On a Mk3 the front of the harness has three white plastic connectors and the back is the taillight and turnsignal leads.
Start with the taillight leads and string them through the large grommet in the frame above the carburetors. Next feed this end throught the large grommet in the flat plate behind the battery box.
Now you can see that leads to the zener diodes also need to be behind this last grommet, so continue to feed the main harness until the first large branches are between the frame plate and the rear fender. This should allow the taillight lead to easily reach the rear of the machine and your zener and rectifier leads will be in position and the low amperage leads for the starter solenoid will be alongside the solenoid., etc. Follow the wiring diagram's wire colors for what connects where.
Ground points are the cylinder head, inside of the headlight bucket, and on each Z-plate, as well as the heavy starter ground from the crankcase bolt to the battery.
As for a picture, I wish you had posted a couple days earlier. I just ripped the old harness off my Mk3 cafe racer in preparation of building a cleaner new harness with a 4 fuse panel in place of the inline fuses in the headlight and on the relays I have installed.
