Audi Repair: 1996 A6 Quattro Coolant Fans, a6 quattro, slow traffic

Question
My wife's A6 recently over heated while driving in very slow traffic for a long time.  No engine damage luckily, but I tested the car and it appears there are three failures which seems bizarre.  The relays are okay, and there is 12V at each of the 30-pins of both relays, but not at the 85-pins.  I also tried jumping 12v directly to the collant fan motors and neither of them is working.  Isn't it kind of strange that both motors would fail?

Answer
When the relay is triggered, you should have 12 V at three of the terminals.  Sounds to me that the trigger pulse is missing, or perhaps you have a missing ground.  When you unplug the fan motors, check for 12V but also check for gound.  Yes it seems unlikely that both motors fail at the same time, but don't forget one could have failed  along time ago, and you only noticed when the second one failed.  I would check the connections first, then connect both ground and 12V to the fan and establish if it works.  This could still be due to a faulty thermostatic swithc in the bottom of the radiator.  Let me know what you find,  Jan