What year 750 should we refer to as an appropriate wiring diagram?
If the battery is charged, the wiring is good, the switches good, the bulb is good, and the fuse is good, you have a working headlight. You are certainly mistaken on one of these mentioned points.
Alternately, you haven't paid the proper homage to the Tron god, he is super pi$$ed at you, and nothing you do short of laying the entrails of your favorite pet on the headlight at moonrise will restore you in good graces.
Personally, I have never needed to sacrifice a pet.