It will come on when it feels like it , and wont stop when you tell it to.

I think this is common problem - Does anyone know of how to resolve this?

Does it need to be replaced?

Cheers

Not when putting it in reverse i guess with the front wipers on?

Does it park?

yes it does park but it starts when ever i switch the front wipers on and when they are switched off it carries on.

Also it stops half way then for a second and then starts again

Could be a faulty motor if its stopping mid sweep.

I had this problem on an old Citroen ZX I had... turned out it was water getting into the motor (so infact I had a very early version of automatic rain sensing wiper!)

Yup, the SWMBO's 306 did it after a jet wash. Went away when it had dried.

Must have been water in the motor.

Oh the irony. Non-waterproof windscreen wipers

there is a teeny weeny control circuit inside the motor casing, could be suss....