instrument cluster dimmer

My 1990 C1500 dash has stopped illuminating all of a sudden. All fuses are good, switches are good and all electrical works except that at night I have no dash lights to see speed, oil, etc with. Is there a third fuse or something that is not allowing power to flow to the lights. Its a little confusing but other than that there is no problem. Any ideas / suggestions would be helpful. The headlight and dimmer switches are new as of yesterday.

If you still have tail lights its probably an instrument panel grounding problem, instrument panel lighting and tail lights are almost always on the same fuse

thanks Ill llook into it.