sticky passenger window and not the regulator
 

Hello Fellow Discovery 1 devotees,
I'm hoping to borrow from your experience and expertise on a problem that has me stuck. It's a passenger window that will neither go up or down on a 1997 D1 SE. 62,000 miles. For several months is has occasionally been getting hung up while closing, but after several tries, it would eventually close. However a few weeks ago, it refused to close. It has been stuck partially open since. The internet and this forum are replete with a go-to solution for fixing D1 window problems: replacing a bad regulator. But that's not my problem. Even though the original regulator looked like new, with like-new teflon rollers, I replaced it anyway. No change. The motor has power and seems fine. If I detach the glass from the regulator, I can raise and lower it by hand, but about ⅓ of the way down the glass will bind and drag, and it takes a pretty good push or pull with both hands to make it move through that zone. (Again, that is without the regulator attached.) I have tried cleaning the glass and cleaning out the two edge channels, and I've tried a dry lubricant spray there, but that hasn't effected the bind. Both channel rails and their bolts are tight. The glass weatherstripping looks like new. In fact, the entire inner door is as sound as you would expect to see on a cared for Rover with 60K miles. So may I ask, has anyone seen this problem? Does anyone have any ideas about what to focus on next?

You did not mention if the motor actually turns when power is applied. I think these motors include brushes with tension springs. If the brushes or springs wear out or get stuck, that could explain what you described. It would take a lot of ups and downs for brushes to wear out completely, so more likely is a brush getting stuck half way, or broken. An intermittent problem with the switch or control relay could also cause the symptoms. Probably more likely is the gears in the motor get worn. Not too difficult to take apart and inspect the innards. Can you tell if the motor is still spinning when the window is stuck half way? If so, the gears are stripped.

For binding, maybe something on the frame got bent? Maybe rusted under the felt or rubber? If the glass is held straight, the motion should be very smooth. Try to find the exact spot that is holding the glass. If the glass is not held completely straight, it could bind. If you are completely sure it is not a power/switch/relay/wiring problem then maybe source another motor to swap in.

I have heard of wires getting broken where they flex at the door hinge. In that case, opening and closing the door could act as a switch. I think that would take a lot of repetition as well.

Hi JohnZo,
I'll add more regarding your questions about the motor. The motor will run very smoothly, up and down when it is not attached to the glass. However, when the glass is bolted to the regulator and motor, the motor freezes. It does not continue to spin. it's impossible for me to believe that it could move the window through the sticky zone. It is not easy or smooth to move the glass by hand, without the regulator attached. I've watched videos of how to replace the regulator, and mechanics need to secure the glass at the top to keep it from crashing down on their hands. That is definitely not a problem I had replacing my regulator. The glass hangs up and is not easy to pull down. There is no way it could drop on its own.

I also should add that in many ways, my D1 is almost like new. It was a barn find with only 50K. So, there is very little rust anywhere. The door innards appear basically like a new car would. Nothing appears bent or damaged. I'm sure that an untrained eye couldn't tell a difference between the regulator I replaced and the new one I installed.

I wondered if maybe the glass guides twist through age, and that is what was keeping the glass from moving smoothy. But they appear new and straight, the felt channels seem perfect, and the bolts that hold them to the door frame appear tight and like new. That is still a possibility, through, but I don't have any experience on that. All my D1s have been new (in the 90s) or nearly new. I still wonder if maybe these rails and channels warp through age, or does the glass warp, ever? I don't think that it would take too much distortion in either to cause the window to bind. I have no experience with that.

...oh, and I can also add that there does not seem to be a catch point where the glass stops when I'm raising and lowering it by hand. I'd say that it gradually tightens into a bind beginning a third of the way down.

I would sort the binding 1st. That may have caused the motor to wear faster than normal and lost the power (dead brushes, burnt armature) necessary to lift the window - hence why it will work without attached to lift mechanism.
It is possible the door was replaced at one point and re-assembly was done without care - ie lower guide rails not properly aligned. If its binding in the lower 2/3's - the lower channel is where I would go next....loosening the lower channel bolts to see if the binding goes away or reduces.

My 98 with 130k and some rust has no issues with windows (regulators have been replaced already). I dont think the channels warp or twist but Im not in the south or desert.