Your wiper home position 'sensor' might need a little attention.
Your wiper mechanism consists of a motor (worm drive) driving a plastic gear wheel which in turn moves the linkages connected to the arms.
On the plasic gear wheel is a metal contact that links two spring contacts mounted in the cover (which in turn 'inform' the control system that the wipers are at the 'home' position).
You could have some dirt affecting the electrical contact or the sprung arms have lost a little tension.
Investigating would require removing the wiper mechanism but this isn't really such a big job, if you're handy with spanners you could have it off in half an hour.
Other than a dodgy connection or wiper stalk, I can't think of anything else it could be.
Have a look. Hth.
Your wiper mechanism consists of a motor (worm drive) driving a plastic gear wheel which in turn moves the linkages connected to the arms.
On the plasic gear wheel is a metal contact that links two spring contacts mounted in the cover (which in turn 'inform' the control system that the wipers are at the 'home' position).
You could have some dirt affecting the electrical contact or the sprung arms have lost a little tension.
Investigating would require removing the wiper mechanism but this isn't really such a big job, if you're handy with spanners you could have it off in half an hour.
Other than a dodgy connection or wiper stalk, I can't think of anything else it could be.
Have a look. Hth.