The rear wiper/wash does work not when the control stalk is operated. However it does move briefly as the engine is started, stopping when the engine fires!
It will also operates randomly whilst driving, apparently independantly from the control stalk! There is power to the fuse positions, the fuses are good, I can find no chafed wires around the rear door, but there is no power at the motor.
My guesses are: Relay ( where and which one?) or control stalk.
Any ideas please?