What will cause the dash lights and all the gauges to stop working only when the headlight switch is activated?

I've had intermittent recurrence of this problem for a while now but it usually
clears up when I restart the truck.  The headlights, tail lights, brake lights, turn
signals all work properly.  Inaddition to the dash not functioning. the two turn
signal indicator lights, the bright light indicator, and a buzzer all activate.