1994 Chevy Truck headlights

If the bulbs are good I would look at the dimmer switch. Its located at the base of the steering column.

I did not mean replace the switch, I meant try testing for voltage there. The headlight switch sends 12 v to the dimmer switch then depemding on whether it is on high or low determines which wire gets power from there. So use a test light to ground and probe the 3 wires at the dimmer switch. One wire should be hot when lights turn on, this is power in, a different wire should have voltage on high beam and the other wire will have power on low beam. If that is good then you must trace the wire for a open from the dimmer switch to the headlight bulb