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Hello all,
I have a 1997 993 Cabriolet and the motor drive on the convertible top works fine. The problem is when it reaches the point of locking just above the windshield, it stops when it hits the two switches next to the locking stations. The top could have been ever so slightly bent, but the guide posts on the top align with the holes they mate to, so I don't think that is the problem. I have to manually drive the motors to close and lock the top. I can then open it again just fine with the motors (most of the time) to the full open position, and then close again and the problem repeats. Is this a problem with those two switches next to the locking station on the frame, or could it be tied to some other area of the electrical system? I have had a respectable 911 mechanic look at it, and he seemed to have fixed it for a short while, but then the problem started again.
Thank you for the link. I have watched this video and used it to repair a broken latching motor where the gears were stripped, just like in the video. Works well. However, my problem seems to be different. The latching motors are working fine, and the locking arms do rotate on command (at least when opening from the locked position), so I'm not sure that it is a problem with the electrical connection to the latching motors.
This set of testing instructions may also be helpful in isolating the problems (microswitch, locking gear, or ECU itself): http://forums.pelicanparts.com/porsc...sting-diy.html. I have the opposite problem (left switch sometimes failed to unlock but recovered after a few retries) that I still haven't got time to look into.
I reached out to Loren at Systems Consulting (https://www.systemsc.com/index.htm) and turns out he lives about 15 miles from me in Southern California. He came over this past Saturday to help me troubleshoot the problem. Summarizing the problem, opening and closing of the latching motors was intermittent, and often would not work at all. The drive motors to open and close the top seem to work fine, but often they would stop well before the top opened (or closed). Here is what we did:
1. Confirmed that the two limit stiches that are mounted to the gear mechanism just behind the passenger seat were working and positioned properly. In particular, you don't want the upper close switch (top fully up) to engage during normal operation. I learned it's only there to protect the motor if the motor keeps driving the top after it closes.
2. Checked the resistance on each of the two switches next to each of the latching motors. Used an Ohm meter. The driver's side was functioning properly, but the passenger side had no response. Problem no. 1 identified.
3. The switch in no. 2 above doesn't explain the intermittent opening and closing by the drive motors. Loren brought a refurbished convertible top ECU with him and we changed it out with my current one. See photo below for all the solder issues that Loren identified. It's not obvious to my eye, but it was to Loren's, and I'm sure it would show up better under magnification. Anyhow, the replacement ECU fixed the intermittent problem with the drive motors, and all is good there. I understand that the majority of problems with these tops is typically the ECU.
4. Back to the switch next to the passenger side latching motor. Took the switch off and manually actuated it (pushed down the lever arm inside the switch), and it worked fine. The problem was that there is a spring that has a cantilevered element to it that actuates the switch when the black button hits the top of the car frame above the windshield. This cantilevered part had broken, so the switch was not actuating. Doesn't appear that you can repair this with a replacement spring (please let me know otherwise). A new switch cost about $250. I can't find a used one. However, what Loren suggested, and we did, was use a paperclip to make a jumper across the two holes in the connector, and then reinstalled the switch unconnected. Sorry, but I did not take a picture showing the broken cantilever part of the spring and the jumper arrangement.
5. Both latching motors open and close on command now, and the drive motors work fine on both open and close commands. Not sure I need to spend $250 to replace the passenger-side switch at this point, but I probably will. So nice to have this top fully functioning. I've lived with this problem for too many years.
Thank you to the Rennlist community for the recommendations and to Loren for coming to my house to help troubleshoot the problem.
03-27-2023, 11:52 AM
Convertible Top Switches
