Wiper self-park explanation
Starting with the 'Running' diagram, power is provided through the green wire from the fuse. It goes into the steering column switch at connection 54 where it is passed to connection 53. From there it goes via the light green/red wire to the plug on the wiper motor which passes the current through the motor to earth, so the motor turns.
The motor plug has a switch in it controlled by a lump on the main cog in the wiper motor. Usually the lump is out of the way, but at one point on a revolution it contacts the switch and breaks one connection and makes another. So for most of the time, the green wire is connected to the light green/brown wire, but when the lump contacts the switch, the light green/brown wire is connected to earth.
So for most of the time, the power is applied to the light green/brown wire, but because there is no connection in the steering column switch, it goes nowhere.
Turning to the 'Off but not parked' diagram, when the steering column switch is turned off, the connection in the steering column switch number 53 is swapped from being connected to 54 to being connected to 31b1. Now this is the light green/brown wire that is still being given current by the green wire through the switch on the wiper motor. So the motor keeps turning until the lump comes round again and switches the light green/brown to green connection off and the light green/brown to earth connection on.
This is the state shown in the 'Parked' diagram. No current is flowing through any circuit because the green wire isn't connected to anything anymore.
One thing to bear in mind is that if the switch on the wiper motor develops a fault which means it makes the light green/brown to earth connection before it breaks the light green/ brown to green connection, all the current is sent straight to earth - a short circuit that will blow the main fuse. In a new or well maintained motor switch, this shouldn't happen, but if the switch is old, corroded or the springiness of the contacts gets sloppy, it could. This will result in the fuse blowing just as the wipers park.
