well this is the embarassing bit. I actually had an unrelated problem with something else in the tailgate about a year ago which I fixed, but I think I loosened the 3 bolts holding the regulator motor and forgot to re-tighten them and eventually the tailgate window failed.
Having taken it all out, I can't see much wrong with it, no cables are snapped, and the motor is working.
What puzzled me was the white plastic tube with a spring that comes of the bottom of the motor had popped out. What is this thing? I think I worked out how to put it back together again but I'm not clear what it is for?
When I took the unit out all the wires were loose, should they be tight?
The manual I have isn't much use and this thread just says 'reverse the removal' instructions. Could you maybe do we a quick step 1...step 2....etc...?
Very much appreciate your help!