I was visiting my daughter who has a 2000 A6 2.7 Quattro automatic with 109,000 miles on it. She started the car this morning and immediately it had an electrical problem that she had not had before. The driver's door ajar symbol was lit and the fasten seat belt chime wouldn't shut off. When she turned her lights on, there was a chime like when you turn the car off and leave the lights on. Her driver's door light at the rear of the door (the red one) was lit as was the light in the driver's foot well and wouldn't go off when the car was shut off and key removed. The interior lights stayed lit and didn't go off when the door was shut. Finally, the light on the passenger window lock on the driver's arm rest showed the right rear window lit and did not change when the button was pushed. All windows are functioning normally as are the headlights, running lights, and high beams. There is no issue with the battery or the alternator. After the car was driven for a few miles, the chime went off but the lights inside stayed on, even when the car ws shut off and the key removed. I disconnected the batter for the night so it doesn't go dead. Just on a hunch, I left it disconnected for a few minutes and then hooked it up again but the interior lights stayed on. It is easy enough to shut off the interior lights overhead but the door and foot well lights are another story. I looked for a door sensor figuring that it might be broken but couldn't find one? She has no shop manual so I can't look anything up. Nearest Audi service is very far away and she uses her car every day for work as she is a traveling nurse, so it is a problem getting it to a service center. Anybody have any ideas of where to start? Thank you for your help.

 

I would start with the Driver's door switch. When the door is open, the contact is closed which allows the lights etc. to function. If there were a bit of water in there, then even when the door is closed you could still have a closed circuit due to the moisture. I don't have my car nearby to check, but it should be an easy fix.

 

Thank you kentetsu. Seems to me that thee are a lot of failures in that switch.