I had this once on a Ford Orion and i feel the solution should be the same, front wipers used to stop at the point you switched the wipers off and not return.
Found it to be the relay unit, only a few quid to replace and you will find the relay in the fuse/relay box either under the bonnet by the battery or on the rear of the main fuse board located inside the car below the steering wheel area.
You should find a diagram of the relays and fuses in each of the locations on the reverse of the cover you remove telling which does what and its rating.
Garry
Found it to be the relay unit, only a few quid to replace and you will find the relay in the fuse/relay box either under the bonnet by the battery or on the rear of the main fuse board located inside the car below the steering wheel area.
You should find a diagram of the relays and fuses in each of the locations on the reverse of the cover you remove telling which does what and its rating.
Garry