There is no signal or switch it goes by physical stops, there is pinch protection built into the body module I believe but I believe everytime you hit up or down it will send current to the motor.

 

I checked the pinch protection by holding a rolled up towel at the top of the window. It did function normally. This feature is controlled by a contact inside the top trim piece.

There must be some way for the motor to get a signal to turn off. Otherwise, it would continue to run always. Since I don't see any switch at the extreme limit of both ends, I assume the motor senses that it has reached its limit by the amount of resistance it encounters.

The only other limiting means I can think of is that its designed to turn a set number of times. Adjusting this would mean there must be a way to time it. I may take it apart again but I'm fairly confident any timing involves the placement of the carrier (to which the glass is attached) in a different position. I believe there is only one way to assemble the unit and mine does work.

The unit I have was subbed after 1999, possibly to address this issue. The design is much simpler but the mounting is different as well. I may look at the one installed in my 2002 M5 to see if it can be adapted.

I've found an el cheapo on eBay for $55.00.

 

I believe that there is a difference - early and later regulators. I am not sure of the change time

 

Yes, there is a difference in the configuration of the unit that doesn't mount to the old style.

I have ordered a new motor only, for $35.00. Should be able to confirm or dispel my theory that the motor itself somehow controls motor shutoff.

 

The stupid forum won't take pictures again today(LOL magically they're here) ... DIRECTLY FROM WDS

for E39 12/95 -09/98

End-position cut-out
In automatic mode, the drive is switched off by way of current measurement. On reaching the end position, the drive is blocked temporarily thus resulting in an increase in the power intake. This increase in power intake is detected in the door module (front windows) or in the rear module (rear windows) and the drive is switched off.

For E39 from 09/98

End-position cut-out
In automatic mode, the drive is switched off by way of current measurement. On reaching the end position, the drive is blocked temporarily thus resulting in an increase in the power intake. This increase in power intake is detected in the door module (front windows) or in the rear module (rear windows) and the drive is switched off.



They are the same for end position detection. I can upload screen shots when they work of the wiring.

 

Thanks for this ferris. I believe the problem is solely with this door. All of the others seem to work as they should.

Th replacement motor is due in Thursday. I'll post back with results.

 

You open the windows??!!

 

What?

 

WTF

 

 

Can't say I have seen this work but the claims in a 540 forum I read is the issue is in part 1 and something slips preventing the surge in electricity. That is what they are replacing. They are not cheap. I can say that on E46s they get replaced often and seem to fix issues you can't see being related to that part.

https://www.realoem.com/bmw/enUS/showparts?id=DE93-USA-02-2000-E39-BMW-M5&diagId=51_2250

 

Yeah, I know what that's about. The clamp that holds the cable to the wire comes loose (breaks) and the wire still moves but it's disconnected so the window stays stationary. I have fixed the problem by bending the clamp back on and using JB Weld to make sure it stays put. Whe I replace the motor on this one, I'm going to use JB Weld as a prophylactic since I have done this so many times.

I was on a trip once and BOTH regulators went out in the rear about 5 minutes apart.

This aparent motor problem is the first time I have seen this failure mode.

 

I received the motor today. I'll post back when Ive got it installed.

 

I think it's going to be the windows switch since that does the current check, would be interested to find out your results

 

I'll get the regulator motor installed tomorrow. The Right Rear door switch seems to be working as designed. Light press opens and closes, stopping when the switch is released but continuing to full opening or closing when pressed beyond the detent.

I may try replacing the switch first based on your response.

 

I didn't have a motor problem. The switch was fine. The cheesy method used by the manufacturer wasn't strong enough to bear the strain of operation.

The problem:

The carriage is almost to the top in the above pic. The carriage has a rubber bumper fitted into the bottom that bears against the aluminum mounting when the carriage is fully down. Why this wasn't done for the top as well is beyond me. If the aluminum mounting that's behind the black guide had been bent forward at a right angle, a bumper (exactly like the one at the bottom) could be inserted into the square hole that exists in this poorly engineered model, and there would never be any problem from this cause!

Closeup:

Problem viewed from the Back:

Should look like this:

The pic immediately shows where the main stress of the fully open window should impinge. The aluminum clamp isn't up to the task of keeping the collar abutted to the backing plate.
The Repair:

Common failure point:

Reinforced:

This regulator had a better design than I've seen in some others. They are naked clamps without any kind of surround. I filled this one with JB-Weld© anyway.

 

Thanks for posting your attempt on improvement. It will be interesting to see if these steps do actually improve/extend service life. Keep us posted.

 

Epoxy in that will work. I have done tons of E46 which seem to be more problematic and only had one fail but the bracket was seriously damaged and missing a big chunk so many that one was just a glob of epoxy. Not what I would call a quality repair.

 

Your job looked brilliant. I do the same thing to brand new ones when I could not save the original. The only one I had fail was that one glob one but had to do something, ordered the part and made the window close. Owner was not suppose to open the window but rolled up to Tim Hortons drive thru and forgot.