SLK 170 wiper fault - Won't stop!

[smart-t]

Hi.

The wipers on our R170 SLK 200 (2001) seem to have developed a fault.

Once they are started by twisting the stalk, they will not stop when the stalk is twisted back to the off position.

Strangely, if you use the washer jet they eventually stop, but not in the normal off position (sometimes half way up the screen).

I'll check the fuses later on, but has anyone got any suggestions? Is the stalk simply knackered?
Thanks

 

[BlackC55]

I would be thinking more along the lines of a motor fault.