The workshop manual page 9195 states:
Right Hand headlamp;
Low Beam: white/tan
High beam: white/grey
Earth: Black.
Left Hand Headlamp;
Low Beam; white/dark blue
High beam: white/light green
Earth; Black
If you are sure everything is working and you can't locate the high beam wire then turn on high beam and test each pin, I would go for the passenger side as removal of air box is way easier then stuffing around under the header tank.
Tried to upload pdf but too big............