Had a chance to investigate the wiper situation.
i removed the steering wheel (needed two g clamps, some 19mm ply and 8mm studding, nuts and tape).
i next took off the cowl over the switch gear.
the wiper switch assembly was only partially available as it clashed with the ignition assembly which i did not want to move at this time.
however i inspected the wires as best i could and upon wiggling the wires (two grey ones)that seem to join the assembly from the stalk internal switching it worked.
Nogging tomorrow so i needed to reassemble to be able to steer.
at least i now know where the trouble is. if it occurs again i can plan for switch gear removal and a proper plug inspection.
meanwhile i have full control of the wipers again.
many thanks gentlemen for the tips and comments.
