BMW F31 Electric Folding Towbar Being Bench Tested.

My towbar would not fold away. When pressing button to stow it, it would just click a few times and refuse to move, then leaving me with a flashing red light in the switch and a check message fault on the idrive screen.
Took it off the car, stripped it off the mounting bracket (the 4 big bolt holes on the black part), then tried to work out how it worked.
Seems to all work from just the one large worm drive, with the outward rotation of the ball being in the middle of the 3 stages. Kind of hard to describe but hopefully video makes it clear.
In the video it appears that the black part moves, but on the car this is bolted solid and it is actually the green section and tow ball that move.
Very clever and well designed and engineered in my opinion. Made for BMW by Westfalia. Well done!
The fault? Well nothing found really, I just powered it up on the bench and it worked fine! I suspect it had got a little stiff and wasn’t folding due to too high a current being drawn on the car (and sensed by the car’s module) which then cut the power.
On the bench, straight off a battery with no control circuit, I didn’t have this issue. I just had to very quickly cut power at the end of each cycle.
Greased up all moving parts and refitted covers. Fitted back on car and it is working just fine! Happy days!
Thanks for watching.