Audi Repair: audi A4 2002 cooling fans draining the battery, audi owners, relay switch

Question
The other day I came out to an audi with a dead battery and because it was 6 years old I assumed it was time to replace it.  I picked up the car with the new battery, drove to work, came out to leave and the battery was dead. Jumped it both times.  Back to the repair station and a new theory that the cooling module has two speeds and that the high speed fan was not shutting off, hence draining the battery. So that very spendy thing was replaced and I went to pick it up and it wouldn't start.  Today after much troubleshooting I'm told there should have been some kind of relay switch for the high speed fan with the new part that wasn't included and it had drained the battery again. Does this all seem plausible?  I'm driving a rental that the station is paying for, and I have no reason to doubt them but I'm wondering if other audi owners have been plagued with this problem.  Thank you very for any light you can shed on this problem...and I hope I haven't mangled the terms too badly.  Kathy

Answer
It should be fairly easy to determine what exactly causes the battery to go down.  It sounds like the dealership is just throwing parts at the problem.  If the new cooling module did not fix the problem, ask them to switch it back with the old one; you shouldn't be paying for their poor diagnostic skills...  Your old module is probably OK and if it is indeed only the relay switch needed, that's is all you should be paying for.  Let me know how you get on,  Jan