Hopefully the following will assist the many of you experiencing problems with your rear wiper motor.
Approx. 6 months ago my rear wiper began to stutter and judder and eventually stop. Therefore, at my 3rd year service I asked the garage to look at it for me. They came back to me and stated that it needed a new motor costing about £90 + servicing!
However, I knew they had not looked at it as the retaining screws had not been touched.
So as not to hand over my hard earned cash needlessly, I decided to look myself.
Firstly I took off the inner plasic cover exposing the motor and actuator and gear. (This was a job in itself-carefully prise off the cover releasing the inner retaining clips, after removing the four screws).
I then pulled the connector and hose off and then released the nut from the wiper arm from the outside and then released the three allen nuts securing the motor etc and carefully removed them all from the chassis.
First unscrew the silver plate exposing the actuator and gear and check that the grease has not solidified or the mechanism has not rusted. This was fine on mine so I moved on to the motor itself!
NB When you remove the motor keep the worm gear pushed in as you do so therefore preventing the alternator from coming out (and causing big probs!!)
Once the motor was removed from the housing I turned the alternator and worm by hand and cleaned the dust from the brushes and checking the resistence whilst turning giving a reading of 3 ohms plus.
(Resistence before was varying from high to low)
I then reconnected everything and bingo - good as new and saved myself a bundle.
Hopefully this will be of use to someone (as the other threads were to me).