Dylan-

Green and Blue are the R/L wires, Yellow is power, Black is ground (it's attached to the steering column, not the stalk switch), and Gray is the high beam wire.

The Gray wire is not used in the US market cars, and the other end on the Gray wire can be found wrapped up in the wiring harness in the engine compartment (Driver's side by the "Overdrive" relay) with a red and black wire.



The black wire is +12V. Red is not used. If you connect the black wire to #85 of the sugar cube relay, and the gray wire to #86, you will get that relay to "click" when the turn signal high beam switch is pulled back. Then if you add +12V (like from #15 of your OD relay) to #30 of the sugar cube relay, you will get a momentary +12V at #87 of the sugar cube relay when the high beam switch is pulled.

Paul