This took me a few weeks to get this straight and it's also what lead me to joining this forum! This allows for ALL switches to function as they should when it comes to your electronics ONLY. Lights, horn, etc.. I'll be posting another file for the Mechanical wiring in the near future as well.
Couple things:
I didn't bother including things like the Turn Signal Buzzer as I personally decided to 86 it but it's as simple as wiring it in to the indicator "ground" and grounding the circuit through the buzzer. Same for a license plate light, just wire it to an aux out if it's a standalone bulb. When it comes to the brake light, this will depend on how you'd personally like it to behave and what style of light you're running as well as just what makes the most sense for you. Consult the M.unit instruction manual for a full list of recommendations and options. Lastly and possibly the most complicated, the Lo/Hi switch. In this wiring setup, I have the M.unit set to keep Headlight on at all times when Ignition is on. This allows me to use the Hi Beam side of the switch as the control for Hi Beam function. When it's flicked on, Hi Grounds out and signals to M.unit to activate Hi Beam. When it's flicked to Lo, there is simply no input going to the M.unit at all so it just reverts to what it's configured for and turns lo beam on again. I couldn't remember what colour the brown wire was that acted as the ground for the High beam enabling the high beam switch to function (either Br/W or Br/R). I've already wrapped the wiring in loom and didn't like the idea of undoing it for something so simple. You can always use the continuity function on a multimeter and test each individual wire to determine this.
If anyone notices any mistakes I may have made, please feel free to reach out and I can make an edit. This diagram is true to colour for the wiring layout in the SUPPLEMENT TO CB750 K6 ('76) portion of the Honda CB750 Shop Manual on pg. 252.
Good luck!
