All fixed, many thanks for your advice and support. In the end it is quite easy to remove, 2 screws from right to left hold the wiper stalk and then 2 screws from left to right hold the light/indicator stalk to a semi-circular clamping plate. Simples!
After cleaning the contacts to no avail I discovered it was the female insert in the connector block that had worked its way out and lost contact with the male pin. Probably been like that since the car was built but just worked its way loose.
I think I have earned a cold beer in the sun!
Chris
