cooling fan wont shut off

[Brice Warnick]

This also happened to me. I frooze my ass off last winter because my fan
ran all the time.
I discovered that a parts supplier has been selling the wrong switch for
years now. 
The radiator fan switch used on most older Audi models is the 3 pin
Wahler brand.
The part no is 321 959 481D. This is a 95°/102° switch and is the
correct switch to use.
There is a supplier that has been selling the
321 959 481 Wahler switch which is a 85°/93°.
The temp ranges are clearly stamped on the switch. The non D switch is
rarely sold even in places like Arizona. The non D switch will make your
radiator fan run all the damn time.
Was I pissed when I found out that I had the wrong switch.
If you have ever replaced this switch and still have the reciept look it
up and see. If not you will have to pull the switch and is 85/93 is
stamped on it you have the wrong one. You need the 95/102.