I have had my truck for a month. I have followed the manual on how to turn the foglights on and they didn't work until I turned the dash dimmer control to the right detent. I left it there and turned the headlight switch off and turned the engine off and the lights remained on and warning alarm sounded. So I turned the dimmer to the off position and the lights went out. When I operate the dash dimmer with the lights on it will turn the headlights off is this normal?