Windshield wipers run on one speed fast.

most likely the switch is bad.i think yours is the same as an 2002 a6 quattro.the switch alone is around $200.00 at most parts places.napa,orly,adv,az.there is alot involved in replacing this switch.you have to remove the steering column,among other things.you may want to research on how to do this or seek professional help.good luck.