Im stumped.. Wife hijacked the audi for a weekend trip or id go look around... Have you tried running the engine yet? If so i would scan for fault codes.. Whatever that thing isnt connected to may trigger a fault code because of it andthat would tell you something.. If that makes sense?

 

You're missing a whole bunch of stuff there.... but the plug you are refering to connects to a group of wires (all with rubber jackets) that are clipped to the fan shroud. They go aroudn the bottom ot the fan shroud but I did not see where they terminated, but it looks like it has something to do with either the fans or a sensor on the radiator. I took a pic but I'm not sure I'd be able to figure out how to get it on here... I will try

Good luck.

 

whats that saying "a good mechanic always has parts left over" or in your case a wire lol

 

haha^