Hey all,
Im pretty new here (to the forum, and to Audi's) so what I have to add might be old news, but I felt like sharing it anyway.
Lately I have been having a problem with my 99 A4, 1.8T which is that the door locks have been randomly cycling (locking and unlocking), and just today my windows were randomly rolling themselves down part way, and my alarm seemed to go off about as soon as I got into the house after leaving the car.
I searched here and it seems like lots of people have been having similar issues but no one seemed to have the answer.
So I got to looking through the manual and messing with fuses and what not when I noticed that I could faintly hear the trunk lock motor going nonstop, cycling on and off even when I wasn't hitting the door locks.
When I dug in to investigate the motor I found a puddle of water about an inch or so deep inside the right rear fenderwell and the motor contacts had been taking a bath in it since my driveway is inclined. Once I pulled the motor and took apart the housing, CAREFULLY drying everything inside and cleaning/drying/re-greasing the plug contacts, things seem to be just fine. *fingers crossed*
Anyway, in case folks are having issues that's at least one place to check.


(and I still can't figure out how the water got in there, but I will be keeping an eye on it)

 

I am facing the same problem but i haven't been able to fix mine......sometime in october(during the rainy season) my power windows, central locking , sun roof all went out at the same time....and i tried so hard to fix it but all to no avail ...and just as i was about to give up on the whole issue...it just started working again...after we had a heavy downpour.but it goes off and on...and sometime my hazard light just come on after parking my car for a while. I hope someone sees this post and helps me....
Where exactly is the fenderwell?

 

You have the moonroof? Check out your rail drains...