My left headlight (low beam) is not working 80% of the time:crybaby2:.When it is not working there is no voltage going to the headlight for low beam(yellow wire).Right light works 100%. Where does it have a relays or control unit that needs to be replaced ? Is it part of rotary headlight switch ? My car is 2000 S430 with halogens.Fog lamps,High beams,marker lights works 100%. Makes no difference if headlight are activated automaticly or manually turn the knob resolt is the same Left low bem is most of the time dead. Any help appriceated .