Thought I would add my experience with this...
My drivers side latching motor has been working on and off for years. I have removed the motor, cleaned, inspected it and the limit switches and found perfect operation. Put it back into place and worked fine for a few days, then stopped again. I have operated the drivers side latching motor so many times with a screwdriver that I was about to wear out the screw slot.
I have read this string of posts many times.
Then yesterday, magic.
I had the top working great and put the top down for a nice drive.
But fog rolled in in the morning and I needed to put the top up for the morning part of the drive. Again, drivers side latch would not operate... getting very frustrated.
Left the top down, drove to work, re-read this string of posts.
Then I thought about what had changed that could have impacted the operation of the drivers side latch.
Only difference between last time I checked everything out and the latch not working was I had a passenger. Hey, wait a minute, a passenger!!!
I went out at work and tried to put the top up. The drivers side latch would not operate. I put my foot over on the passenger side floor and tried the top.... perfect operation. Removed my foot, would not work. Put my foot back, worked perfect.
Took the car home, excited and found that the socket for the module was loose in the computer brain. I could ever so slightly move it and make the drivers side latching motor work and not work. I could also feel the clicking in the module when it was properly secured and I could feel nothing when the module was slightly not in place.
It is all fixed now, and quite a relief. :)
Just passing it along....
Paul Hatfield
Engines In Back
88 Carrera Cab (triple black)
65 356 C coupe (black on black)

Cab warning lamp linked to power window repair? I just fixed the passenger side power window on my 1991 964 Cabriolet. It involved removing both the window motor and the window regulator from the car. Now the passenger side window works, but the cabriolet top warning lamp is on when the top is up or down. Any ideas on how the window repair could have caused the convertible roof warning light to go on, and how to fix it?

For 964 owners-is it possible to loosen the control unit through the gauge holes as opposed to reaching up blindly from under the dash?

Oh I have a bad feeling that this is what I'm going to be doing soon.
Thanks for the fine work.

Just to add to 356Paul's comment, this was exactly what I ended up finding out when my left motor worked intermittently, or not at all. It was the #2 plug on the brain. It was wiggly on the brain connecting pins, and while pressing it down and working the top up/down switch, everything worked!I opened the cap on it, and noticed that the pin sleeves inside were just loose, and pushing away from the brain pins when plugged in. To fix it - maybe not what the Factory would recommend - I just put a few layers of black electrical tape on the inside of the cap to exert more pressure on the sleeves when closed, and it now works consistently. If you're having a left side motor issue, I'd definitely look here first!
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'88 911 Carrera Cab

Ecu
 

Wish I found this forum thread before i spent a month becoming a troubleshooting expert on this, if you guys are still around. I have a '88 930. Everything was tested, i can easily bypass the ecu, by pressing the switches right on the control unit to release both locks at one time and then lower or raise the top, also i can do it the troubleshooting method one by one. Checked all limits, grounds. Sent out my ecu to ecu doctors, they said the ecu is fine and sent me a new one just in case, still same thing. I can raise and lower the top, lock it and unlock it, bypassing the ecu all day perfectly. but when i use ecu and press the switch( which i swapped also just in case) the ecu just clicks and nothing happens. One thing i noticed is when i raise the roof in bypass the convertible top light does not go on( it does in the test, and when i turn the key to on position). otherwise i have been done everything i can imagine, tested it 3 times over with the testing procedures, and still will not work on its own.. i don't know what else to do.

I am new to the forum. I followed "notfarnow"'s excellent tutorial non troubleshooting convertible top. Everything checked out OK, with the exception of Plug #1 contact #15, not getting 12v on radio feed. Any ideas on how to solve this issue would be greatly appreciated.

Read here under Porsche, Cab Top; https://www.systemsc.com/problems.htm

Hello,

just having issues with my automatic Top ( electric one) . we have carried out all tests following the Notfarnow procedure up to dashboard switch
we found the lock motor weak sometimes and after a white , the gear was loose and not functioning
we opened it and we found the Large brass wheel broken.
i don't know if we have broken it where we tested it on 12 V with direct wires as the micro with is not there to stop the motor ?
micro swith inside is ok
it was a bit difficult to pull out the cam but i did it BUT impossible to remove the large brass wheel on the shaft
i tried with a heat gun and WD 40 but it doesn't want to move even a bit ...
i am thinking to use a small ball bearing extractor but there is not so much clearance between the brass wheel and the casing

do you have any ideas how it pull out the brass wheel ? because of course i prefer to buy the fixing kit ou can find with vendors like PARTWORKS.DE or others ( i live in France)

Do you think we should add a something to secure the motor when testing it on 12 V ? adding a relay ?

Thanks for your support

When naive/improper cab top ECU troubleshooting goes bad:

http://forums.pelicanparts.com/uploa...1755381220.JPG