'98 XK8 Intermittent Wiper Fault

[will]

Hello, I have a nuisance fault with my wipers - no matter which setting, they run for fifteen wipes and then stop anywhere on the windscreen, usually in the line of vision! Guess it is a relay probelm or the control stick on the column. Fed up with manually controlling the wipers when it rains on long journeys - any thoughts / suggestions before I go poking around?

[DaveEFI]

Sounds to me like two faults. The parking circuit should always park the blades at the rest position - unless the power to that is removed, like say by switching off the ignition. It is some form of switch driven off a cam in the wiper gearbox. Older ones used a full current switch - newer may use a micro switch and relay. If that is faulty, the lack of a ground or whatever may confuse the delay timer.