Will you take a look at your instructions, I saw you had Gr/R and thought you confused it with Blue/R. I mistakenly referred to Blue/R as Gr/R in my response.
I think I got us confused.
Yup confused, blue/red wires are used for the oil pressure switch in the Honda wire diagrams. Doesn't normally route to either bar control.
Right hand control has a master kill switch "ON OFF". Along with ignition "OFF/RUN/OFF" and starter button.
er... the "OFF/RUN/OFF" is the engine "kill" switch.
the "ON OFF" is the a lighting control switch.
Inside the right hand control:
To ignition switch: Bk/W & Bk
To starter button: Blue/R & Y/R
To headlight kill: Brown/W & Bk
The blue/red must connect to the black in order to supply 12v to the solenoid for starting.
Bk/W and Black to Bk/W and Black in the harness This is coil power (the Kill switch function)
To control only the headlight power connect the Brown/W wire from the control to the Black/Red In the 77 wire harness. You'll need to connect the black wires to the black wires in the bike harness.
This assumes the rest of the 77harness/wires, connections are intact.