cabrio top question

[Tnathan]

I am back to working on my favorite topic: the cabrio top on my 1999 996. I had been working on the top, and tried closing the top. However, rather than travelling the correct distance forward and latching, it stopped about 4 inches from the front window and the latch tried closing completely missing the microswitch/pocket. I kept holding the rocker button and the top would increment forward a 1/2 inch, or so, and tried to latch again, and again, and again until the top had moved forward enough that the latch could grab the pocket and trip the microswitch in the front window frame.

I purchased a durametric and ran the calibration program that operated the top from full open to full closed. But when I retried the roof operation again with the rocker switch, the top still acted as noted above. I also looked through the shop manuals, and I am not getting any fault codes (nothing). Any ideas what else I could try? I saw on here some posts talking about checking the ohms of potentiometers, or that all the microswitches are being tripped. Is there a switch that I could reset to get the top to move further forward before deploying the latch hook? Thanks.

[EleCTriCT]

please check the fluid reservoir. I find top travel is greatly affected by low fluid.

in the back under the carpet, top ups are usually only a few ounces...

cheers

[Tnathan]

Great idea, I forgot to mention that I tried that first. I got a small oil can opened the screw cap on the rear wall of the hydraulic reservoir and tried to pump in as much as a could with a small diameter hose attached to the oil can. It started to leak back out each time I pulled the trigger to squish more fluid in. I can't imagine that I got more than a couple of spoonfuls in. And franky, I have never noticed any hydraulic fluid leaking. Do I need to open some other port so as to release a vacuum. If I am missing something please let me know.

I also saw some posts regarding resetting the potentiometers to 6 ohms. Not sure why they would be suddenly off or whether they could cause the issues I am having.

I then paid for a durametric and ran the calibration program. The roof went all the way forward (completely closed) and hummed a little and then all the way back open and the motor hummed a little. I assumed that this would communicate to the controller where fully open and fully closed were to the pumps. However, when I tried to close the top using the rocker switch stopped again about 4 inches from closing. As I hold the rocker down, it would move forward a 1/2 inch and try to close the latch. Again and again until the roof came far enough forward to catch the roof and close.

Any other ideas out there? I am out.

[987_RDC]

Go read a thread where I fought a similar situation on my top. For me it turned out to be the final rear latch. The calibration sequence will not complete unless all the switches work. I also got confused by the top reversing before latching, it was a red herring on mine.

[Tnathan]

Thanks for the comment. Your thread is what gave me the idea to check the potentiometers/microswitches. I just wanted to check to see if anyone else had any success with checking all of the microswitches or if something else could explain what I am seeing. Frankly, I wasn't sure how to do this, and I was a little skeptical that this might be my problem given that the durametric isn't giving me a fault code. Did you happen to have checked when you were troubleshooting to see if the microswitch was faulting? Without a fault I hate to just going through the car wrenching parts hoping to stumble on a cause. Thanks for your thoughts.

[987_RDC]

There was no code. I had to manually work through each of the micro-switch steps. Turns out a few of mine were busted but the final latch one solved it. Maybe check the side drop "wings" and be sure the switching are being properly depressed. Might need to bend the metal tabs on some of the switches to get them to fire sooner. I had to adjust my top switch (inside latching mechanism) that way.

[Chuck996]

I also have a 1999 Cab and I am just like you guys -- I have spent more time and money on the top than any other part of my car. I am about ready to just put the hard top on and say #### it.

Chuck

[Tnathan]

Yep, that is about where I am at too. I am just going to weld a hard top on to prevent the temptation of tryin to fix the cabrio top. The whole experience is maddening. I am sure it was snazzy when people saw all these complex switches and pumps working at the dealer. But 1o years latter it just can't be fixed.

My local dealer says this is body work, and I should take it to a body shop. The local body shops say it is a foreign car that they don't have any experience with and would cost me more than it is worth for them to try to use my car to learn on. The shop manuals seem to talk about calibrating and adjusting the roof, but they seem to be purposely written in a way to obscure what you actually have to do to fix anything. And, in my case, I am being told that I have a faulty microswitch that I have to search for like a where's waldo experiment, despite the rather complex system of checks and sensors, no one thought it would be a good idea to provide a diagnostic to actually tell you whihc of the mulititude of things that can go wrong has gone wrong. And, the auto calibration frunction doesn't seem to . . . calibrate anything as near as I can tell.

[Tnathan]

I wanted to,give you all am update on some of the things I learned.

1. Ptec helped me find my issue. The pitch fork part on the front of the cabriolet latch has a spring to bias it downward. My spring had come off and the pitch fork had stuck up, so the car thought it had hit the front window and would trigger the latch prematurely. Put the spring back in place and it works like a champ now.

2. As an aside, I also created another issue for myself,which I fixed. The ball and socket tension cables between the rear bow and the car are held on to the bow by little balls which thread into the bow. Mine had unscrewed itself. I presumed the nut inside the bow was press fit in. Unfortunately that isn't the case. Once the ball unscrewed itself the inner nut was lose inside the bow. I tried to retread but the bolt had turned sideways. I started contemplating dismantling the bow which looked like it could turn into hours of work so I could spend 5 sec to reattach the ball fitting. Instead I used my magnetized part grabber and rubbed it along the bow to pull the lose bolt into place. i held the bolt in place with the magnet and rethreaded the ball connector. Just thought I would pass along.

[rdoine]

I would have never thought of using a magnet to solve your loose nut problem. That was very inventive! I'll have to try to remember it for future reference.