Quickly, I'm working on a 2003 C320. Has a battery drain (about two days to kill it). I get no interior welcome lights (from the unlock signal, or the door switch). When the individual interior light buttons are pressed, they illuminate dimly for the brief moment the switch is pressed, but never come on. Instrument cluster warns "inop light sensor", but the auto headlights function fine. If anyone has info or this circuit diagram I'd truly appreciate it.