dodgy wipers! Any help please?

Hi,
My wipers were fine, then suddenly they changed to, the setting where goes once then the few seconds later goes again, well that changed to go constant with no break. same time when you turned them off, they wouldnt go right to the bottom, but just stop wherever.
Few weeks on and theyve stoped working all together.
I checked fuse and thats fine. Must be either wiper motor or stick right? Any ideas which i should try change first?
Thanks very much, any help much apreciated.

Dan

wiper stalk

if they aint stopping in the right place the park switch would be a good place to start. While yer there you can check that the motor is getting a feed from the switch.