The OP is past that point, but good info nevertheless

 

After looking at the armature for the motor I pulled from the door, I think I understand why the Fonzie methods works. Or at least have a theory. Observations:

1. The brushes in my non-functioning motor looked to be in nearly the same condition as the brushes of the new motor I purchased from MINI (yes, I compared them).

2. The commutator bar did have brush dust on it, but hardly enough to be responsible for failure. I have seen far worse commutators that were still functioning after going through a whole set of brushes.

3. There were wear marks to the stack teeth of the armature core. With the axis of the armature oriented vertically, the wear marks on worn teeth were either at the top of the armature core, at the bottom, or both, and it varied around the circumference. This wear pattern indicates that the armature is wobbling about the shaft.

4. Inserting the armature shaft into the motor housing, I could feel play between the shaft bearing and the bearing seat. This would allow wobble to occur. The wobble could easily be induced by the worm gear on the shaft engaging the worm wheel/regulator drive gear. It looks to me like MINI (or BMW) did a poor job specifying the tolerance on the shaft bearing/seat interface.

5. The wear marks on the shaft teeth frequently terminated not at the slot but mid-tooth, with a sharp step from wear spot on tooth to less worn tooth.

I think a sharp step on the tooth is hanging up on the magnet and keeping rotation from occurring. In my case, where there were multiple wear marks and steps to hang up on, the problem wouldn't go away for long. The more wear marks and steps you have, the more likely you are to hang up on one.

I think the Fonzie trick works because you switch on the juice at the same time as the vibration drives the armature core away from the magnets enough to begin rotation. There must be a timeout on the switch circuit which works by current sensing. If it senses no current (because motor is stuck), the voltage stops being applied. That would lead to needing to time the switch and vibration more or less simultaneously, with the vibration closely following the application of voltage. The more wear, the more likely you are to hang up on a step.

I think one temporary fix for this would be to file the steps down so there is a smooth transition.

I wonder if some sort of spacer could be be added between the bearing and bearing seat to take out the wobble.

My $.02

 

Tony, I wish i read your quote above before I tackled this project. I am on my 3rd for the driver side and the passenger side is failing. I replaced both at the same time. I'm ordering OEM so I don't have to deal with this BS anymore.

 

This just happened to my 03 MCS yesterday. Worked fine the day before and yesterday I noticed it was stuck in closed position.

As dumb as it seems, a few swift blows with the sides of my fist to the area just above the speaker grill while activating the switch freed it up to work again.

As posted in an earlier observation, this certainly has to do with a motor that is getting lightly stuck and needs a little "encouragement" to free itself. I also think this will be temporary and will likely reoccur at some undetermined time.

Since this is an easy fix, I'll keep using the method until complete failure. As a side note, I noticed in the past that the window would "chatter" when rolled up or down on occasion. This is probably the tell tale sign that the motor is on it's way to failure. Make note if this happens on yours.

Happy motoring!

 

I have an 05 r53 and my window had the same problem! Except mine was making grinding noises so we pulled the regulator out opened up the motor and saw the wire was frayed beyond no return so we are looking to order a new regulator and motor anyone know where to get quality 05 r53 driver door regulator and motor?

 

Right here: Now check your production month/ year , there was a split in 6/2005 . Also for the 6/205+ you will need the adapter plate also. Motor, regulator, and window tool linked below. Thanks and good luck.

http://www.ecstuning.com/Mini-2005-Cooper-R53-S-Coupe-L4_1.6L_W11B16A/Interior/Window/





Thanks