BetaSteve

2005 E55, symptoms as follows: with headlight control set to auto, all lights on all the time, dash and hvac panel also dim all the time = car thinks it’s dark all the time. Windshield wipers in position one (auto) do work - sprinkle some water and wipers do their job, I’m thinking these two systems use the same sensor above the mirror. Disconnect sensor and wiper position one no longer works. Continuity check on ribbon cable all paths good with no bleed over to any others. If I’m correct and it’s a dual channel sensor has anyone had one channel fail and the other still function? Or is the headlight day / night sensor somewhere else?
Thanks in advance for any and all response, I’ll not be so impatient this time!