Headlight electrical problem

Does anyone have any information concerning high beam headlights that will not come on? My '93 Ford F-150 truck high beam headlights will not come on when the light switch is pushed forward for the high beam. The indicator for high beam comes on the instrument display when the switch is engaged but the head lights themselve do not burn at all. They suddenly stopped working a week ago on my way to the ranch. Also, does anyone have a wiring diagram for the make and model year?

I know that it would be weird to have them both go, but have you checked the lamps?