91 C2 Cab top won't seal
 

The top folds up and down with no problem, but when raising the top to close it, the top reaches the winshield top brace as usual but the motors that usually seal the top do not seem to engage. So the top just sits there with a 2 inch gap between the top and the winshield brace.

The top folds and falls into place just as it always has - with no unusual noises. I'm looking for possible causes, troubleshooting and of course the best way to fix it.
Any suggestions are appreciated!
Steve

Do you unzip the rear window?

Doc

yes the rear window is always unzipped when I operate the top, I learned that the hard way.
The top operates normally to the point where the leading edge is about to lock. Then it does not lock. The problem seems to be with the motors that lock the top to the windshield frame - they do not seem to work at all. Any ideas?
Steve

Check the micro switches at the transmission, I think it is on the passenger side. One has to be closed, made contact with the arm to tell the front motors to operate.

Hope it is that simple...........:thumbup:

Check the microswitches on the convertible mechanism - transmition. Most likely, the upper one is in the wrong position and to early gives a signal that closure of the roof is complete. If this does not happen every time probably, the cause is loosen the three (or four) screws securing carbio or central screw on transmition.

and what does the window have to do with it?

I have owned my car for 8 years and have never unzipped the window and never had a problem with it. I gotto say tho that my top stays down about 9 months of the year and maybe only raise it a few times a year to wash the car sometimes.

I've never had a problem with the window being zipped or unzipped. It can crease a bit if you leave it zipped, but one afternoon with 95deg sunshine will fix that.

Thanks for the microswitch info, I'll look into that asap.

As for the rear window unzip question...Porsche recomends the rear window be unzipped to remove the tension on the roof as it closes. I've been told by more than a few cab owners that it's especially important in colder climates where the cold can cause the window to crack or spiderweb. I had to replace and repair the cab motors a few years ago when they broke from the mounts (@ $2k) and I was told that this is often caused by not unzipping the window and/or stopping and starting the roof mid cycle. So...it takes me 5 seconds to unzip it and now I ALWAYS unzip it here in NJ USA.

^^^ What smongiovi said.

Doc

91 Cab top won't lock - details
 

well I opened the panels on the passenger side and the top microswitch does indeed get depressed upon closing. I checked the electrical connections and all look clean and secure. I've included 3 pics - the roof as it looks after going through the complete close cycle; the crank/transmission in the open; and then in the closed postion. In the closed postion, you can see the top microswitch is fully depressed as I believe it should be.
If you folks have and other ideas let me know otherwise it's off to the repair shop with it.
I do appreciate the help
Steve

one bad incident does not make a rule. I'd say the starting/stopping is more at issue than the window. Don't quote me if yours breaks.

These switches can go bad. Another easy check would be to put a small jumper wire at the connector bypassing the switch, or closing acting as the switch. I cannot remember if there are switches at the top motors or not, but I do know there are wires that run through the roof. If one or more of those are broke........... ugh.

Hi All:

Okay I know this may sound a little strange but try disconnecting the battery, wait 30 seconds, reconnect the battery and then try cycling the top again. I have my rear top transmissions disengaged so that the top can manually operated but I still use the electrical top locks. Every third time of cycling the top the lock motors cease working. Its almost like the system is in some sort of fault condition from the previous operation. By cycling the battery it seems to clear the fault so the top lock motors work again. This won't solve your overall problem but it may help get the top locked down. Of course getting the top to open again may cause all sorts of other issues if the top lock motors don't cycle but the rear transmissions try to operate. I will be watching this thread with interest because I intend to get the top back back to fully automated form this summer.

The upper microswitch is definitely too close to the roof rack, just loosen the screw and slide the black plastic to the left, then close the roof.
You have precisely adjust the location of upper microswich (open and closed), because roof should stop just above the window, and then locking motors close the roof. When roof is closed upper microswitch schuold be touched by roof rack. Locking motors have microswitches too.