It would be easy for me to blame the ignition solenoid in the electrical bay (streetside forewardmost) right away, but others here are more versed in such things, specifically your particular dash. It would be useful to know if anything else is not working; it would help zero in on the culprit. Driving lights, windshield wipers, overhead fans, dash A/C... they are on the ignitioned side of the solenoid like the instrument panel is; are they working? The dash lights are probably on the same circuit as the headlights, which are on the "hot" side of the solenoid and don't depend on the ignition, so I assume the headlights work?
Joel