I have a 2000 a6 quattro 2.8, the aux fan that is next to the serpentine fan isn't working. I checked for loose wires or something not connected and everything seems normal. I found a blown 40 amp fuse underneath the steering wheel. I replaced that and the fan started working. The next day I ran the car with the AC and everything was fine. After work I drove home with AC on and the car started to overheat when I got home. I opened the hood and the aux fan wasn't working. I checked the fuse and it was blown again. I replaced it again and the aux fan still won't work. I tried another 40 amp fuse and it still isn't working. The car runs great and won't overheat unless I turn the AC on. Maybe I need a new fan?

 

Try disconnecting the fan from the harness and supplying it with 12 volts. If it turns on you know the fan is good. if not, you know the fan is either dead or on its way out.

If it works I would then begin to explore whether or not you have a short (frayed cable) between the fuse and the connection, or perhaps a faulty FCM.

 

Thanks. Anyway you can show me where the fcm is located and if possible how to disconnect the fan from the harness? sorry this if my first time working on an Audi.