frozen Cab top?

TonyAdam · 04-02-2007, 11:53 AM

Yes, I'm a knuklehead. I accidentally tried to put my top up with the boot still on. Now the top is frozen won't go up or down. What can I do to get it working again?

AFJuvat · 04-02-2007, 12:46 PM

Welcome to the forum.

Please put the year and model of your car in your posts.

Also, a detailed description of your problem (is it making any noises etc) make it much easier to help you.

TonyAdam · 02:50 PM

Sorry, It's a 1990, 911/964 C2 Cabriolet. It's hopefully clear that I'm talking about the convertible top.

kurquhart · 04-02-2007, 08:13 PM

I know nothing about cabs, but the scenario you describe could easily have blown the fuse - have you checked that?

TonyAdam · 04-03-2007, 04:31 AM

Yea, that was the first thing I checked, it's ok

AFJuvat · 04-03-2007, 04:58 AM

Ahhh Cabriolet tops, the one job that you knew when it came into the shop that it wasn't leaving for less than $1000 and probably more than $2000, and sometimes as much as $7000.

Sadly, those aren't typos.

Back to the problem. First we will start with theory of operation, and then progress to troubleshooting. Sorry if I am long winded, but cab tops can be tricky.

Theory of operation in a few easy steps kind of like a computer programming flowchart:

1. Button is pushed to open top - IF microswitches in top are depressed AND upper OR Lower microswitch on passenger side transmission is NOT depressed, THEN rotate locking motors to open position. Microswitches Inside locking motors send signal to turn "top is up" warning light on.

2. IF Microsiwtches in top bar are open AND microswitchs on passenger side transmission are not depressed, turn on electric motors in back of car, retracting top.

3. IF bottom microswitch on passenger side transmission is depressed, AND Microswitches inside locking motor indicate latched unlocked, AND microswitches on top bar are open THEN Stop cabriolet top retracting and turn off "top is open" light

To Close:

Button is pushed: IF # 3 above still applies, turn transmissions the other way. Until one of the following happens.

1. Top microswitch on transmission top is depressed - top stops immediately, regardless of top position

2. IF microswitches in top bar are depressed AND top microswitch on transmission is NOT depressed, turn locking motors to 'Lock" position until internal microswitch in locking motor indicates "lock", then turn out "top is open" light.

On to part 2 in next post

AFJuvat · 04-03-2007, 05:39 AM

You are going to need a helper to troubleshoot.

Remove the back panel behind the passenger seat. It is held in with 3 screws, then it lifts and slides out. At the bottom center, remove the sound insulating pad, and you will see the drive motors. On each side, secured with a clip, are the drive cables. remove the clip and pull the cable out.

Inspect cable - if one side is distinctly shorter than the other, it is time to replace the cables.

If they are ok, leave the cables out and disconnect the wiring harness to the motor. Use a volt meter across terminals 1 and 4 (I think those are the correct terminals - it will be the red and brown wire) and have your helper activate the switch to open. You should get +12VDC at those terminals.

If you have voltage, try jumping the motor directly. If it spins with direct jump you have a problem somewhere else in the system. If it does not spin, you have a bad motor.

TonyAdam · 04:28 AM

Thanks, How do you jump the motor directly, hook it up directly to a car battery?