Do your other dash lights work? Ashtray, heater controls should come on as well.There should be a ground coming off the back of the speedo cluster to the center top mounting screw, put a jumper from this ground to a clean ground on the dash and test. Also check to see that the wiring harness is plugged in properly to the back of the cluster and that you don't have a blown fuse. If they still don't work try a different headlight switch.
