Working a 2003 Mercedes Benz ML 500. Light switch on auto at night, headlights and fog lights do not turn. Light switch on Manuel first setting, parking lights turn on but headlights do not turn on. I press the fog light switch on, low and high beams turn on and the high beam stay on regardless if I manually try to turn off or on and of course the fog lights are off. I know the fog lights with the fog light switch on , go off when turning the high beams on, cause that's a feature required by law. But having no headlights unless I press the fog light switch on? Is this as setting problem? Is there a module that controls the settings? Can it be a sensor? Or a switch?