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  #1  
Old 07-30-2004, 07:29 PM
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Soft Top Problems

Hi

Today tried to lower soft top and it would not work. Rear deck opens and back part of hood folds but the two latches on top of the windscreen do not open. Was working fine when I last used it last weekend!

Of note I have replaced both electric window switches. However as mentioned in earlier post the passenger side window had stopped going up and down for the past two weeks, it is stuck in the up position. ( Used to open passenger door for the past two weeks to allow hood to fold).

Earlier, passenger electric window did not go down with soft top operation and I used to lower it manually with switch. I think Bobterry99 did mention something about a position switch in the door that also stopped the "one touch" down operation which also affected the soft top operation.

My question to Bobterry99 is can the faulty window position sensor in the door stop the soft top from opening?

Also in order to access fault codes previous posts mention shorting socket 10 to ground, do you do this with the ignition on or off? Further posts also state something about connectors X11/12 near the passenger footwell, does this apply to my 1990 SL as well or can I get all of the fault codes via the diagnostic connector under the bonnet.

Any help from Bobterry and others is much appreciated

Regards

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  #2  
Old 07-30-2004, 10:04 PM
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You should list your year of the car in your profile. Assuming this is a 1990, the side windows HAVE to be down for the top to operate past this point (rear top bow vertical), There is a switch in the bottom of the door on these early models, and if the window doesn't fully lower and close the switch on both sides, it doesn't work. So if the windows will operate, try lowering them both, then try it.

Gilly
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  #3  
Old 07-31-2004, 03:27 AM
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Thanks for reply Gilly, car is a 1990 model. I have changed signature to show this.

Kind regards
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  #4  
Old 07-31-2004, 05:05 AM
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The ignition must be on to retrieve codes from the 16-socket diagnostic connector X11/4. You short socket 10 to ground for 2 to 4 seconds to read and for 6 to 8 seconds to erase. I suggest reading-out and erasing any existing codes which may be stored before troubleshooting your current problem.

Your car has an X11/12 connector in the footwell, but this is not for reading codes. It is used for putting the soft top controller in a special diagnostic mode which checks the states of all of the limit switch inputs.

Remember, when your car's top operation ceases you should continue to hold the top switch until it flashes. This ensures that the controller has stored a fault code.
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  #5  
Old 07-31-2004, 07:43 AM
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Hi Bobterry

Have got codes 17,28,29 from the controller, what do these mean?

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  #6  
Old 08-01-2004, 01:57 AM
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17 = Left front door "window down" limit switch
28 = Speedometer signal is missing
29 = VSS signal (wheel speed from ABS control module) missing

If you got code 18 (limit switch for the passenger door), then it would clearly indicate your current problem. Are you sure you got 17? And I wonder if the other two are old codes that won't return when you erase them.

It's easy to remove the door panel and access the switch, by the way. I think a couple of people including Tecqboy have posted a procedure.
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Old 08-01-2004, 05:03 AM
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Hi Bobterry

I am based in London UK and car is RHD so left hand window is the passenger side. I think this is the problem, will try to tackle it early next week. (No dealers open today so cannot buy any parts today).

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  #8  
Old 08-01-2004, 03:26 PM
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What doesn't make sense to me is that you said you were opening the passenger (left on your car) door to enable the top to work, but I am quite positive that the soft top module doesn't monitor the open or closed door, it needs to see this "limit switch" closed (by the lowered window) before it will progress any further than it does (rear bow raised to vertical and front bow latched down)......... So if you have a window that won't fully lower, that should be the problem right there.
I don't believe the other codes are a problem. If you read codes with the car stationary (duh!) and the engine off, you'll get codes like this on the earlier models. Later models the criteria was changed to set these types of codes because MB realized that these codes were meaningless if they were always present.

Gilly
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  #9  
Old 08-01-2004, 05:15 PM
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Hi Gilly

The passenger window has been inoperative for about 2 weeks or so. I cannot explain why it allowed me to lower the top last week with the window up and the door open. I only opened the door so that the hood would not foul the window. (To be honest I only raised it and lowered it once)

The only difference between now and last week is that I put a new passenger window switch in place thinking that the switch was faulty. Maybe the old switch had some fault in it that somehow fooled the computer?????

Kind regards and thanks for input
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  #10  
Old 08-01-2004, 10:13 PM
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Nope, it's pretty straightforward that these switches in the bottom of the door (inside) have to be "closed", ie pressed down upon by the window mechanism for the top to operate past this point you are describing, I've seen this happen many times, very "classic" symptom of a window not working, or a bad or misadjusted window limit switch. Can't really fool it. Well, short of removing the door panel and pressing on this switch, then I guess in a way you "fooled" it. All the early models like this "know" is the switch is "closed" it doesn't know if you're finger is closing the switch or if in fact the window is down. Maybe when the "hood" operated that one time the switch in that door was actually stuck in the "closed" position and since then has become unstuck? Only good explaination I can offer. The answer I would say is to fix the power window on that side, then hopefully the "hood" will operate. Unfortunately there can be several causes for this window to not work, including the switch, which I realize you replaced, but also the motor assembly and actually the soft top control module can cause an inoperative window.
Gilly
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  #11  
Old 08-07-2004, 10:55 AM
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Hi

Today the passenger window started to work with the switch. However the "one touch" feature did not work and also the passenger window does not lower when hood is lowered.( This is how it has been since I bought car, I usually lower window manually with switch).

However it appears that the hood will lower even if I do not lower the window with the window switch. This is quite strange since I was lead to believe that this could not happen!!

To top things off it has now stopped working again!- No window and no hood lowering now.

I have taken door trim off and located limit switch. I tried pressing switch in and out but it makes no difference to either window or hood operation.

Does anyone know if all my probs. are caused by a dodgy limit switch? If so how do I access the connection to the switch to replace it.- The door has an "inner skin" held on by bolts which I was not too keen to remove. Are the connections behind here?

It seems strange that a dodgy limit switch would stop the window from working at all.

Thanks in advance
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  #12  
Old 08-07-2004, 05:45 PM
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A limit switch won't keep the window from operating.
Yes, you'd need to remove the inner door panel to access wiring connections.
You could have bad wiring in the door jamb which is creating the on again-off again nature of your window problem, it could also be occasionally making the the lower-limit switch for that window short out, which allows the soft top to operate by opening the door (changes the wiring in the door jamb by opening or closing the door). This would make the most sense as to these seemingly unrelated problems, could also be the soft top control unit, I'd rather doubt that possibility though.
As far as the one-touch not working (assuming the window is working at all (the window probably just needs resynchronization.

Gilly
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  #13  
Old 08-12-2004, 07:49 AM
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Hi

Update on situatiom:

Limit switch appears to be doing its' job. On pressing switch manually(unclipped from door), top lowers and raises. When switch not pressed top does not proceed to unlatch from the windscreen. Therefore soft top function seems OK. However passenger window will work after leaving car for a few hours. Then after raising and lowering a couple of times will stop working all together.

I have checked power going to motor with a meter and this shows 12 VOLTS + or - depending on wether pressing up or down. In addition one touch sends continous 12V until I press limit switch (MANUALLY) therefore implying that circuit is OK. In addition lowering soft top sends )+/-12V to window motor thus implying that outputs from controller are OK.

I then disconnected the inputs from the door and passed 12V from a battery directly to the motor and nothing happened. Therefore is the motor faulty, I would think so. However someone told me that a motor either fails or works and would not give an intermittent fault.

My next question is can I replace motor without removing inner door panel which kind of scares me!

Kind regards and thanks for help
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  #14  
Old 08-12-2004, 08:26 AM
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Hi
Happy news. Sounds like the metal tab which is supposed to depress the limit switch is a hair out of adjustment, I've seen this before too. It will be simple for you to figure it out, just 1 bolt I believe is loosened and you can move this tab around. Just lower it maybe 1/16" or so (a few mm, sorry) and I believe you'll have fixed it. You'll need to figure out the best position of the window to access the bolt and tab, I forget where the best place is, there is a slight trick to that, I don't think it's possible with the window all the way down, there is no access to it way down there, but you can see it.

Gilly
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  #15  
Old 08-14-2004, 07:33 PM
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Smile

Final update I hope!!

Window motor out and gears cleaned. There was a lot of dirt/grit in the gears which must have been intermittently causing an obstruction. motor worked after disconnecting it form the gears. After cleaning and re-assemblying motor it worked. Adjusted the limit switch as well. Windows and soft top now FULLY operational!!

Thanks to all for your input

Kind regards

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