Hi James, there is a relay for the wiper it is mounted on the fuse box inside the car, it's relay#2 should be red in colour if you can get access to the motor it should have two wires going to it white/red & violet/blue the white/red is the supply to run the motor and the violet/blue is the wiper park command supply you might find that to run a new wire from one of the motor mounting bolts to the earthing bolt on the hatch might cure the fault
nigel, February 2008