86 trans am light prob

Hey all. ive got an 86 Trans Am. Recently i was drivin in the dark, and all my instrument, heater control panel, and shift pattern lights went out. when i got home i realized the tail lamps and parking lights did not work either. And once i turned off the headlight switch the headlights did not fold down. I checked the fuses and found them to be good. I replaced the headlight switch and no luck. It was suggested to me that maybe the headlight actuator relays were shot and that could cause the problem. I am skeptical of this, but i wanted to see if there was anyone else out there who had any similar probs or know what the problem could be. Any help would be greatly appreciated. Thanks.