I have an issue with the rear wiper on my focus. Some time ago, the wiper started to play up on a particular setting. If I select the option for the wiper to automatically do 2-3 strokes and then stop, it only moves a small amount of the way across the rear window and then stops, in the wrong place. If I select the same option again, it will continue its stroke to the end of one side of the window and then return a small amount and then stop again. If I select the option where it will run continuously then there is no problem and it appears to function as normal.
I have already replaced the relay, thinking that this may be the cause, but this has not resolved the issue. However I did purchase the relay second hand from ebay so there may be every chance that this was sold to me already faulty.
I am guessing it could be the motor, but would this not also affect the wiper movement if the continuous option was selected.
Any advice would be greatly appreciated. Thank you.