Driver Window not Dropping

[no_substitute]

Yea, Thanks Jim - I have tried this step repeatedly with no resolve.

[Strawfordt]

Okay, I have been in the window regulator manufaturing business for about 13 years. I've been mostly dealing with North American domestic regulators.

Is this a sudden problem or one that has existed for ever?

If this has suddenly occurred here's what I can recommend you to do.

You will need to remove the door trim panel to allow you to see inside the door
The window regulator should be a 2 rail, cable and drum type. The motor will have a plastic drum housing that contains the cable drum that winds and unwinds the cable. The cable will feed into the drum housing in two places that will be approx. 180 degrees apart from each other. If you can see where the cable is fed into the drum housing you should also see that there are 2 springs that take up the cable slack. When you change direction you will see one side of the cable collapsing the spring and the other side of the cable having the spring move to extension. This is done to take up the natural slack and / or stretching of the cable. I suspect that you will see the side with the spring extension being > 25mm from the housing. BTW when you reverse your window the springs will switch from extension to compression and vice versa.

If you are seeing excessive spring extension then in all likelyhood the cable has either come off of one of the pullies, a plastic end piece has failed on one of the conduit ends or the cable assembly was built to long to begin with. For what ever reason what you are describing is an excess of free cable causing the cable drum to wind cable without causing the glass to move.

The glass drop function in the window regulator and the express up function are both controlled with a logic controller and hall effect sensors in the motor that send a signal to the controller allowing the controller to count the rotations of the motor armature. If you can detect time and speed of the motor then you should know position.

If you still have problems let me know. In the meantime i'll try to get you a picture of a Box W/R to highlite the areas I'd be looking at.

[denverpete]

Originally Posted by Strawfordt

The glass drop function in the window regulator and the express up function are both controlled with a logic controller and hall effect sensors in the motor that send a signal to the controller allowing the controller to count the rotations of the motor armature. If you can detect time and speed of the motor then you should know position.

Ahhh.... But you cannot simultaneously know an objects position AND momentum - Heisenburg Uncertainty Principle

YES! I got to use quantum physics today.... I think I'm going home now....

[Strawfordt]

Originally Posted by denverpete

Ahhh.... But you cannot simultaneously know an objects position AND momentum - Heisenburg Uncertainty Principle

YES! I got to use quantum physics today.... I think I'm going home now....

Ahhhh... right you are. However, i said speed not momentum. The controller counts the time between the revolutions of the motor armature and determines speed.

For the record this is a general description of anti pinch window regulator technology.

I have never workedd on a Porsche project. I have direct experience with Fiat, Alfa, Lancia, Opel, GM, Ford, DCX & Honda. The technology for cable and drum W/R's is basically the same from all parts OEM's. Especially true if you have to control positon of the regulator. There are some other anti pinch technologies but they are not that common.

[no_substitute]

Originally Posted by Strawfordt

Is this a sudden problem or one that has existed for ever?

If this has suddenly occurred here's what I can recommend you to do.

This happened very suddenly.
The detailed information about how the window regulator works, is this all window regulators or is this specific to our Boxster window regulators?

[RandallNeighbour]

Strawfordt: Window regulators in the 996 and 986 are evidently not made to the highest standards in the areas of durability. I've replaced my passenger side W/R, and I suspect a previous owner replaced the driver's side.

[Seminole_Boxster]

Did you replace the regulator yourself or have a professional do the work? If self, how long did it take? Thanks.

[RandallNeighbour]

My mechanic did it, but next time one of them goes out, I'll do it myself... my Bentley manual in hand. After all, I stayed at a Holiday Inn last night!

[98Boxster98]

This is a good reference for the 986 DIYers:

http://www.bombaydigital.com/boxster/projects/window/

[Strawfordt]

Originally Posted by RandallNeighbour

Strawfordt: Window regulators in the 996 and 986 are evidently not made to the highest standards in the areas of durability. I've replaced my passenger side W/R, and I suspect a previous owner replaced the driver's side.

Because of the glass drop feature during door openings and closings, the regulators typically see a lot of use. a normal front door system without the galss drop feature is designed for 25,000 full up and full down cycles. Other features of the vehicle tied to door opening and closing are requiring 100,000 + cycles before failure.

By the looking at the system design. I'd say that the part is manufactured by a best in class supplier. Too bad the class couldn't be better.

Tom

[denverpete]

I just had the driver's side window replaced and I noticed that it doesn't go up far enough. Maybe needs another 1/4 inch or so.

Is there a simple adjustment to this or will they need to take off the door panel.

I tried the "standardization" listed by MNBoxster and that didn't do anything.

[slithern]

Did you ever get a solution to your window problem? I had the exact same problem and took it to the dealer. They said Window Regulator and fixed it. $604 mostly covered by my extended warranty.