Boxster/996 window issues?

I have seen a lot of window issues in boxsters and 996′s lately.  The general operation of the door glass is simple in the 2 cars.  Basically, when you pull the the door handle (inner or outer), the window glass will drop about a 1/2″ to allow for smooth opening of the door.  When the door shuts, the window will raise back into place.  The same goes for the convertible tops.  When the front release handle is triggered, the windows drop to allow smooth opening and closing of the top.

Now there are several ways the window operation can fail (IE, not drop when you open or close the door, or convertible top).

There are 3 microswitches in the door.  One is triggered by the inner door handle, telling the window to drop when the door is opened from the inside.  A 2nd microswitch handles the same operation from the outer door handle.  A 3rd microswitch is found in the actual door latch mechanism, that tells the window to stay down if you let go of the inner or outer door handle while the door is open.

So some failure modes:

1.  Door glass does not drop when opening the door from the inside:  Culprit–inner door handle microswitch

2.  Door glass does not drop when opening the door from the outside:  Culprit–outer door handle microswitch

3.  Door glass goes back up when you release the either door handle, making it very difficult to close the door with the glass all the way up:  Culprit–door latch mechanism microswitch

4.  Both door glass windows do not drop when operating the convertible top:  Culprit–Convertible top latch microswitch

Recently I had a #3 come through the garage.  The bad thing about #3, is that the microswitch is built into the door latch mechanism, so you have to replace the entire unit if it is bad.  The other microswitches can easily be replaced by themselves.

Replacing the unit involves removing the inner door panel.  There are numerous hidden screws and clips that need to be conquered.  Once the panel is out of the way, you can remove the door latch mechanism.  It is a tight fit, but it will come right out.

Looking at the inner door panel……the mechanism is hid back in there……

The assembly out of the car.  Notice the blue and red wires attaching to the microswitch.

You can see the two small holes that help hold the microswitch in place.  The switch rides on the round cam gear.  In this case, the cam gear (which is plastic go figure) started to separate, and the microswitch no longer operated on material that wasn’t present anymore.

Now the switch is very easy to test in the car.  You can open the door, pull the latch mechanism partially out (leaving the electrical connections in tact), remove the microswitch from the assembly, and push the button.  If the window drops when you push the button, then you have found your problem.  I tried to repair the cam gear in this instance, but the gear was so deteriorated, that it was impossible.  So a new one is on order!

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32 Comments

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Amy Edwards

September 14, 2009 at 3:33 AM

Thank you so much for you post. My window is a typical #3 and I am trying to figure out how to save some money. Do you know how much (on average) something like this would be to fix?

    porschedoc

    September 14, 2009 at 2:24 PM

    Hi Amy,

    Typically the part is about $200 and labor is about an hour to 2 hours to install.

Mike

September 21, 2009 at 11:33 PM

I have a similar problem. Every time I get in my car and put the key in the ignition the windows go down as though i have started to put the top down. I assume the switch is bad but some sites I’ve looked at say replacing the micro switch in the top latch won’t fix the problem. Any ideas how to best fix this problem?

    porschedoc

    September 23, 2009 at 2:36 AM

    I would still start with checking the microswitch in the top latch if the windows are dropping when you turn the key on.

Ryan

October 25, 2009 at 1:40 AM

Hi, my problem is that neither the inside or outside latch will trigger the window to lower. It remains up the entire time and will not close properly when the door is shut. Which switches do you think are at fault? Thanks.

    porschedoc

    October 25, 2009 at 6:58 PM

    Hi Ryan,

    Does this happen on just one side of the car of both sides? I would check the microswitches for the both handles and the wiring harness in the door.

      Rich

      March 1, 2010 at 8:26 AM

      Iam having the same problem as Ryan, “Hi, my problem is that neither the inside or outside latch will trigger the window to lower. It remains up the entire time and will not close properly when the door is shut. Which switches do you think are at fault?”

      My passenger side is the one at fault. I am going in to fix the window regulator so it seems to be the best time to take a look. Any ideas on what the problem is? Could both switches go out at the exact same time? Thanks in advance.

        porschedoc

        March 1, 2010 at 8:42 AM

        Hey Rich,

        I would find it unusual for both microswitches to go bad at the same time, though I have seen a lot wierder things when working on these cars. I would start by pulling the inner door panel and checking the wiring harness, especially where it makes connection to the main harness at the front of the door. I have seen those connectors get corroded with water and cause issues similar to this as well.

      Jim Fagan

      September 24, 2011 at 11:50 AM

      Think I am in the same boat. None of the microswitches are engaging. But all work periodically. Short history of the situation – Had a bad regulator in the passenger side. replaced it easily. Then the window would go up but not down. Took the motor loose from the regulator and he motor would only turn in one direction (up). Turns out one of the pin connectors in the harness connector was pushed inside the housing and wasn’t making connection with the “down” pin. Was able to get it back in its original position – motor went both directions. Put it all back together, re-standardized the window, but now the window won’t drop using either inside or outside door handle – or the roof latch. Micro-switch in the roof was working before this last tear down – now it doesn’t. You mentioned in one thread about the harness connection at the door getting corroded. Could you please elaborate on where the connections are and possible solutions. Because of the sporadic functioning of all of the micro-switches I’m thinking there is a connection issue somewhere in the harness in the door. Think this defines “ghost in the machine”.

        porschedoc

        September 24, 2011 at 11:58 AM

        Hi Jim,

        If you open the door all the way, and look towards the front hinges, you will see the electrical wire bundle coming from the door and attaching to the body of the car. It is a plastic connector held together IIRC by a small allen screw. If you can get the screw out, you can take apart the connection and clean it and see if that helps. My only other guess would be to make sure everything is still connected properly to the door pulls, and door latch mechanism. I can’t remember for sure, but I think there are some adjustments on the regulator itself that you make through the bottom of the door, but will have to go through the manuals to see if they can cause an issue like you are having.

Steve

March 6, 2010 at 10:40 AM

i have a similar issue to Ryan in #3 above. On the passenger side, neither the inside nor the outside door handles will trigger the 14mm window drop. As a note, the convertible top does trigger the lowering of the window. we tested with an ohmmeter the operation of the door HANDLE microswitches and they are fine. reaching into the wiring harness that connects to the door latch mechanism, and touching the large connector, a solenoid is felt and the horn chirps twice… I offer this if any of you have had a similar thing. there are no corroded connections on that plug… We didn’t take out the door latch mechanism – didn’t have the torx for that one… but before we call that mechanism the culprit, I wanted to offer this up and see if anyone had a similar experience and an A-HA! moment.

By the way, we had this issue before and after replacing the window regulator… which I can say was an easy job with this EXCELLENT help. http://www.bombaydigital.com/boxster/projects/window/

Odysseas

April 26, 2010 at 4:52 PM

Hi,
I have a similar problem on the passenger’s side. When I open the door either from the inside or the outside the window lowers and stays down. However it does not drop more than 1 cm which is not enough for the door to close again without hitting the window on the seal. Is this due to the window regulator or the motor of the window regulator? Is the distance that the window drops programmable thru the ECU?

    porschedoc

    April 27, 2010 at 7:49 AM

    Have you tried re-standardizing the window? Start with the door and window closed (up position). Hold the passenger side window button down and keep holding until the window reaches the full down position. Then push and hold the passenger side window switch in the up position until it completely closes. Then release the button, and then push the up position one more time and release.

    If that doesn’t work, then you are likely looking at replacing a regulator.

John Southan

July 7, 2010 at 10:51 AM

Hi, I have a 1999 996 and I had the same issue as #3.
Replacing the door latch assembly corrected the problem.
Approx. $450 for parts and labor.
I have the old assembly and I can see that the cam that operates the micro switch is completely worn down.
This would make me a little leary about buying a used one unless I could check it out before hand.
Anyone have any ideas about taking the old one apart.
Thanks
John

Bill

August 13, 2010 at 10:24 AM

My passenger side window goes down too far and rattles when the window is down and I close the door. The up pposition is fine, no other problems. Does the window have a “stop” for the down position. Any idea for a fix?

Thanks

    porschedoc

    August 13, 2010 at 11:05 AM

    Hi Bill,

    There is an adjustable stop IIRC at the bottom of the door. You will have to remove the door panel to access it. Probably worth a shot to try and adjust it, but you may find your regulator assembly just needs to be replaced.

James

October 4, 2010 at 11:14 AM

Hi there. I have a slightly different problem. The windows work fine (drop 14mm. but when I’m driving along the doors will unlock themselfes (red light extinguishes on door switch) and the internal light comes on,then a few seconds later (sometimes lot later)the windows will wind all the way down. It definately only happens after the doors have unlocked.

Gavin

December 11, 2010 at 11:50 PM

Hi,

Mine is really none of the above with my passenger’s door window of my 996. When I pull either the inside or outside door handle I can hear the motor try to drop the window (so the microswitch is fine) but it barely drops the glass. However the window works fine with the switch inside the car.

Here is my post, any clues?
http://www.pistonheads.com/gassing/topic.asp?t=936524

    porschedoc

    December 12, 2010 at 1:41 PM

    Hi Gavin,

    That sounds like a window regulator that is starting to fail to me.

nicolas

April 18, 2011 at 11:22 AM

Hello
Maybe you could help me.
My 996 C4 cab have a window problem the no longer move, not even when i open or close the doors or the convertible top. I can not open or close anymore the 2 front windows.The rear are ok.
Help is welcome !
nico

    porschedoc

    April 19, 2011 at 7:56 AM

    Hi Nico,

    So neither window will drop anymore when you operate both the inside and outside door handles? Did this occur at the same time? Have you tried reprogramming the windows? With the windows up and the door closed, hold the buttons to drop the windows all the way down (do not release them). Once you get to the bottom, raise the windows holding the button the entire time as well all the way to the top. Then try it.

Blackops357

June 23, 2011 at 11:37 AM

Hello Porsche Family,

Drivers Side Window randomly drops 1/4 in on My 2K Boxster while driving…can tap door or press door panel above inside door latch to correct momentarily until it happens again. Which Micro-switch is the culprit?

    porschedoc

    June 23, 2011 at 2:05 PM

    Sounds like a loose connection or bad wiring to me. I think you are going to have to pull the door panel and start moving wires around with the ignition on to see if you can get it to drop. Could be any of the switches or regulator freaking out.

Brian

September 20, 2011 at 2:50 PM

Please help. Drivers window dont drop when opening door.. Inside or out side handles dont make it drop. Every now and then it will work. Like today is the first time its worked in 2 mounths. Also , today is a rain day. Thinking short? But where?
Thanks 97boxster

    porschedoc

    September 20, 2011 at 6:02 PM

    Two possibilities: the first is the door latch assembly, and the 2nd is the regulator itself. Since it isn’t moving at all, I would guess the latch assembly. Typically when the regulator fails, it will still drop the glass ever so slightly but not enough to clear the top.

Tao

March 22, 2013 at 8:56 AM

Hi, I have a 996, the passenger door window won’t move at all, it’s stuck all the way up. When I press on the rocker switch to go up I heard a the motor trying to go up, when I press the switch to go down I don’t heard anything. I saw in earlier post Jim mentioned down pin being stuck, could that be my problem?

Thanks

    porschedoc

    March 24, 2013 at 9:58 AM

    Possible. You can likely check by swapping l/r window switches, or putting power to the down contact of the wiring harness at the switch.

sam

September 17, 2013 at 7:32 AM

i have a porsche boxster 1999 i’m having a problem with my windows as as soon as i unlock the car and open the door both windows drops down by 2-3″ and i can’t get them up while the roof is up they only operate well when the roof is fully down…any advice please..i live in england and with the every day rain we have over here it’s a real nightmere.
regards

    porschedoc

    September 18, 2013 at 4:39 PM

    Hi Sam,

    Sounds like a microswitch problem with the center top latch assembly. There are 2 microswitches in that assembly, sounds like one is on the fritz.

Niels

September 21, 2013 at 4:43 PM

Hi there,

Just a window problem in the Netherlands…..
Suddenly the passenger window does not move at all any more. It is in the “open door” position (window just slightly down). Nothing happens when I open the door from the in- or outside and the button for opening/closing the window doesn’t work either. I don’t hear any sound of a motor. Can it be a fuse?
I had a rough passenger that had problems with opening the door, could that be the cause (before this everything worked properly)?

Thanks!!

Simon

October 11, 2013 at 1:03 PM

Hi all – I have a similar annoying window problem
I have a 2002 3.2s 98k miles, which has started to have the window not dropping a few inches when using the internal or external handles. passenger side is fine and both drop fine when unlatching and relatching the roof. I have read your posts and thought its the internal 3rd microswitch/latch. tried the window reset too and left the car parked up for a week unused as i was working away. I went to strip the door panel off and the window works perfectly without doing anything. and worked all weekend… i then used it on the monday and the window issue was back. i prepared to strip the door panel again and after a week dormant the window works perfectly…. is something resetting itself while dormant … any ideas as it works sometimes but i dont want to strip the panel and spend on new latches etc if its not going to fix it….. long winded but i am sure you know what this is…
thanks
Simon

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