My no parking problem, after checking the relay (OK),and pulling the wiper motor (OK) turned out to be in the wiper stalk. After pulling the switch out and checking it on the bench it all appeared to be working fine. The contacts all seamed to be making, however when checking the breaker contacts with and ohm meter I found one that wasn't completing the circuit.
If I remember correctly it was contact that's connected to the blue wire in this picture. Cleaned it up and tweaked it a little and it's been fine since.
