I have an 03 A6 3.0 w/ tip. With the key off, an amp meter between the ground terminal and the body, there is about 0.42 amps pulling on the battery. If my car sits for more than 3 days, the battery is dead.
With the amp meter in place, I have pulled every fuse and relay that I know of with little change on this reading.
As a last attempt, I disconnected the positive wire going to the fuse box, no change. Then I checked the other positive wire going to the alternator / starter, bingo...the amps dropped to 0.02. I then disconnected the main cable from the alternator and sure enough, the amps dropped to 0,02. I believe this takes the starter out of the picture.
Is it normal for the alternator to be drawing current with the car off? Probably a bad voltage regulator?
It sounds like one of the diodes in the rectifiier pack is leaking a little elecitcrcity. Most of the time they open up and you get a lot of A/C on the electrical line. When they short you will have a current draw usually more than .42 amps, usually around 2 - 3 amps. An easy way to check is to use an inductive pickup meter and check the power line from the alternator to the battery. I think a draw of .42 amps (420 ma) should take a number of days to drain the battery. Usually, a not to exceed 50 ma is in the normal range to run the clock and keep the computer alive.
I have removed the alternator and have now verified the issue is with the voltage regulator. This is a first for me. The car has been sitting for over a week now (without the alternator), and the battery is fine.
Thanks for the feedback. I will be replacing the alternator w/regulator.