I noticed that my front radiator fans were not running at all, or were running wide open speed. I ran vag-com on the car and got the below code. I asked the dealer for the cost of the part and labor. Part is $299 (8E0-959-501-AB)for my 02 A4 3.0Q. The dealer said the job would be 4 hours labor. 4 hours?? It's right there at the top of radiator, easy to get to. I decided to do the job myself. It only took me 45 minutes. No stress job too. Here's a little DIY.

First, here's the code I pulled from vag-com.



Here's the replacement part.



You have to cut some wires on the old unit to get it out. These four are the same color code and used to splice to 4 fan wires.



Here's the old unit removed. You can see the 4 colored wires I had to cut. Cut pretty close to the unit so you have more available for your splice.



These are the four fan wires that were cut. You can see they are the same color code. They are stripped just enough to receive the crimp.



Another view



With the crimps installed



Here the new unit is installed and bolted in. You have to feed in the left side first, at an angle. There is a metal tab on the unit that slide into a slot on the radiator shroud. Wires ready to be crimped with the others.



Here the crimp connections have been finished. The wires have been tucked and ziptied out of the way.


Another view



Now we just have to snake the main cable to the right side of the engine bay and re-hookup the main plug



Closeup



That's it. Use zip ties to tie down cables at the spots where the old zipties were. Start the car with the a/c off. When you turn the a/c on, the fans should kick on. But they should do this in a controlled speed manner. Well, you know how it's supposed to sound.
Replace your engine covers and feel good about saving $400+ in labor charges to the dealership.