Im going to try to explain this the best I can, I have an 85 firebird and the headlight switch in the car to turn the lights on or off, it has the headlight button, and the button just to turn on your parking lights and then the off button, well normally when you turn on the headlights everything turns on with it parking lights, headlights, tails etc. and when you turn it off everything goes off and the lights go down, well with mine I turn everything on headlights go up and everything works as normal, but when I go to turn them off the headlights stay on, but the parking lights, tails, go off, I then have to hit the parking light button again and then hit off, and then the lights go down and everything is off, my question is why do I have to do this extra step, I tried replacing the headlight switch, but i still have the same problem, I dont know if the other one I have is bad also, or something is wrong with the wiring, any help is appreciated.

 

if the headlight buckets themselves are what is causing your problem I would say try checking the headlight module on the firewall thats located directly above and behind the brake booster.