Volkswagen Repair: electrical/cooling system, vw passat, temperature gauge

Question
I have a 96/97 VW Passat that no dealer can find a problem with, but maybe you can help.  When I turn the car on there is a buzzing sound and the odometer and clock reset themselves.  This does not happen every time, but starts very randomly then slowly progresses to every time and finally the car won't start.  then I have to jump it off and take it to a dealer to get it checked out.  I have had the alternator and battery replaced but the problem still persists.  I just got my car back from the local VW dealer after it had been there 1 month (literally) where they finally determined what they thought was the problem.  They said there was something wrong with the cooling fan and that it stayed on much longer than it should and they replaced something to do with the temperature gauge  for around $40.  Of course, i had the car back for one night and it immediatley reset itself just like it has for the past 4 months.  Do you have any clue what could be wrong?  When they check the electrical system, it is showing all clear and they said they've checked all the wires.  Frankly, I'm so annoyed with this vehicle and want to get rid of it since it does nothing but break down and no one know what's wrong!  (i've been to 3 different VW dealers and the first two blew me off, so at least this place tried to fix it)
Please help!

Answer
Shannon,
I'm very sorry for not replying sooner! I'd help you out if I could but I've never even sat in a '96-'97 Passat, much less ever repaired one. Electrical problems can be hard to find and some take longer than the customer thinks it should and doesn't want to pay for the time spent (especially the dealer labor rates!). If you're near Pa., I know of a few places that could possibly repair the car. Sorry again!