have a 1997 Audi 1.8T Sport Avant with a fault rear wiper. Before it
totally failed it did judder. Having removed the wiper blade the motor
doesnt seem to function.
I have power going to one of the four wires, the Red and Black wire. I
do not get any feed form the other wires.

I do not want to purchase another motor if it's not that. I am not sure
if this has a relay or something else which may have failed. What's the
best way to test the motor, use a temporary feed to one of the cables?

I would realy appreciate some advice as to the sequence of events to
try and track down the problems. Thanks.