Problem with rear wiper - Passat 3B TDI AFN (only short pulse)

Hello,

Thank you in advance for your commitment. I have a problem with my rear wiper
Problem: When I turn the ignition on, the wiper moves.
a small piece, when the rear wiper interval function is activated, also only once.
a small piece, if there was a gap of about 30 seconds in between. Do I press the lever?
further back (Washing), the washing pump runs and water leaks out, the rear wiper
However, this does not impress me. Re-activations are always performed only once.
a brief movement, acknowledged after a certain period of time, with pauses in between.
no response. The windshield wipers function perfectly with all features.
I disassembled the rear wiper and found no loose solder joints or leaks.
noticed a break-in. The engine itself is running, but I haven't been able to test the electronics.
The double relay (377) on the relay block at the front clicks (right relay for front wipers) when the front wipers are activated, but the second relay on the board (for rear wipers?) does not click at any time. If I operate it manually, the wipers also do not work. I can measure 12V at the four-pin connector on the rear wiper motor when the ignition is on (between brown and black/yellow). The two wires in the middle of the connector gn/ge and sw/li both connect to ground when the motor is attached, but when I activate the rear wipers, I measure approximately 6V on both. I cannot measure any pulsating signal with or without the motor. Why are there actually two lines besides the power supply, I thought one would be enough, and what does the electronics do? For assistance, I would be very grateful.
Okay, here's the translation:

so, many greetings from the north...

I think the rear wiper needs the other two wires for right and left movement. Normally, the polarity is reversed, but I'm not sure about the rear wiper!

Is the interlocking on the rear wiper arm okay!? Does the engine (you can hear it) or is it just this small jolt!?

Thank you for the response...
I've now delved a bit deeper.
As it appears, there is a small circuit board with a controller chip on the back wiper motor PCB. The corresponding component is located in the relay. Therefore, the wires will be +,- and the two control wires, similar to CAN-High and CAN-Low. I don't think this is really a CAN bus, rather a slightly simpler system.
The engine is perfectly fine, but the small circuit board seems to be faulty, and this is likely a common issue with VW. The rear wiper motor is probably sold quite often. There is likely also a newer revision.
I was lucky enough to try out a motor from another vehicle, and it works perfectly for me, so it's definitely the rear wiper motor as a complete unit.
Unfortunately, I'm unable to separate the small circuit board into individual components.
In my opinion, the only annoying thing is that the wiper only does what wipers have been doing for thirty years or more, and it's been unnecessarily equipped with electronics.
An OBD-fault diagnosis seems to not have been carried out, so what's the point?
If it were manufactured in a conventional way, I could now save the new part.
Unfortunately...
Well, I now know the problem and am considering whether or not to buy a new one...
Thank you anyway for the response and best regards from the north...