The headlight switch is next to the steering wheel. It turns on the panel lights as well, The rheostat is on the passenger side of the console. It makes the dim dash lights dimmer. I replaced all my gauge lights (actually all the lights except the panel light embedded in the crash pad) with LEDs. I also deleted my dimmer switch. Since I was getting a new dash I had the guy cut a gauge size hole there and replaced it with an oil temp gauge (which really isn't that useful!
).
edit: I almost forgot - the rheostat is suppose to turn, the headlight switch pulls out for dash lights, then rotates a little and pulls out again for head lights. If your rheostat doesn't turn and you want one, I can send you the one that came from my car. Text me.
