I this the one Ian?
https://www.volvoforums.org.uk/showthread.php?t=202838
I keep threatening to do my left headlamp wiper but the "quizzical" expression the car seems to wear has kind of grown on me :
Fairly sure it's just the park switch out of adjustment on it so it seems a lot of work to simply adjust that. They both work at the moment so will probably get left for a while............