the instrument gauge will light up after the car has been turned off. It appears to be a short but dealership could not find anything. Car was hooked up to a voltage meter for a day and 1/2 and no pull. I read that if the radio is left on after the car has been turned off, that the car should automatically shut down the radio to avoid battery drain. I have already had to replace the battery
Why does my middle instrument gauge light up when the car is off? on 2010 Mercedes-Benz E350
by ssh in Bowling Green, KY on January 14, 2013
ANSWER by gmc4me , January 14, 2013
If the light was on there is absolutly no way that your battery did not lose voltage. I agree with it being shorted. That would need to be traced down.