My rear wiper had stopped returning to home for quite a while.
The same problem is posted
here.
In my case, the issue turned out to be the changeover relay (in the left rear on FD i30cw). The contact between 30 and 87a was dodgy (intermittent high resistance, causing a voltage drop when the motor tries to draw current through it).
The coil on the relay is controlled by the stalk switch/control system.
The motor has a 4 wire connector, 1=GND, 2=Switch, 3=Park, 4=IG2.
The Switch connector is driven by the common (pin 30 on relay), this powers the motor.
The Park signal passes the IG2 voltage when not in the home position, and switches to GND when in the home position. This is connected to the normally closed pin on the relay (pin 87a).
The normally open pin on the relay (pin 87) is connected to IG2.
When the relay coil is de-energized, pin 87a to pin 30 on the relay closes and the switch signal to the motor is driven by the Park output, when the motor reaches the park position, the motor stops.
A generic changeover relay replacement was all that was required. A Narva one has the option to slide on to the OEM bracket. I needed to file the bracket ever so slightly narrower to fit in the relay and a dab with a soldering iron serves as locking tab. The relay is behind the left wheel well trim in the wagon, not sure about the hatch.
OEM on left, Narva replacement on right.
