Preliminary findings, and now I'm stuck...
Removed the motor/disassembled it. (have pics (not sure they're in focus, the macro function on my Polaroid is lousy), and will show how to measure the motor without disassembling it...)
Only to find that the problem seems to be in the gears, or better, probably the axle from gear to wiper. I stuck on the wiper to have some leverage and got things going again, but it was hard. For this it is VERY handy that the motor it NOT attached anymore!
I can't get the toothed gears off (there's two metal half ones and a plastic white round one that's driven of off the 'wormwheel' (?, spiral-drive-like-thingy, don't know the english word) of the motor) and I don't know how to disassemble it further. Best idea so far is from my father in law who said, drill a hole, throw IMAL in there (think it's pretty much the same as WD40), flush it with the stuff an hour later, fill it up with grease and seal the holes off.
But obviously, disassembling it, if at all possible, would probably be better!
I did get it to work, but the intermittent problem (stopping half way through a swipe) was back in no time. So I also think that is linked to the gears/axle having way too much friction.
There seems to be a 3-point measuring system what tell the position of the white toothed-wheel, but I cannot get at the underside of the wheel, so haven't figured this one out yet. The PCB that's in there does have three contacts for this system, next to the two contacts for driving the motor.
Will try to continue this if and when I have the time.
PS: aligning the wiper in the end was very hard, as it seems you can make a 15 degree mistake depending on whether you arrest the wiper arm or not while tightening the nut. Haven't found why, but it seems quite strange.
Need AWD info, so that's why I invade your forum with my V70 D5 AWD...
Hope you don't mind...