I have an A4 electrical issue (2003 A4 1.8T quattro wagon - automatic tranny). My windows and sunroof and central locking don't work all of a sudden. There is a faint buzzing sound under the driver's side, foot area (I first thought it was a relay buzzing, besie the fuse panel but it is not, the buzzing is coming clearly from right in front of the drawer of the driver seat. It could be a faulty relay causing something down there to flutter...not sure. Car drives fine, but has limited power to the wipers, and the interior lights are flickering. Buzzing is there even with no keys is the ignition. Anyone have a clue on thisone? THANKS!!! (BTW - all fuses are fine)

 

Open the panel in the footwell and look for the buzzing relay.. Dont know which one it is on your car.. but you should be able to hear it.

 

Wow - it is soaking ringing wet in the floor...anyone else find this problem?? Under the driver's side carpeted foot wel it rnigs out like a sponge! maybe this is why the bos under there is buzzing

 

Its usually on the passenger side, but yes.

 

My GOD! This used to always happen to my 1980 VW Jetta. The mechanic said it was because the drain from the sunroof goes down the front left "tower" right by the relay panel. Now if there is a leak in that line, it will spill water all over your panel. Not saying this is the case with your 2003 A4, just saying that I've seen this before and since Audi is owned by VW, I'm wondering if the issues are similar. Can't imagine they would be with all the time that has passed but hey, you never know.