convertible top electrical troubles..
10-23-2001, 01:09 AM
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convertible top electrical troubles..
My '92 964 C2 (Tiptronic) Cabriolet electric convertible top mechanism has become intermittant recently, and now often fails in one of 3 ways:
-top is completely open and won't close,
-top is completely closed and won't open,
-top is closing normally but then stops just as the top flops down onto the windshield frame.
Turning the ignition on and off repetitively while repetitively depressing the rocker switch that activates the top eventually does the trick, but sometimes it takes 20 minutes or several days of patience to get good results!
When the top is open and won't close, I note that the convertible top dash light does not come on when you turn the ignition on like its supposed to.
When the top is closed, and I turn on the ignition, the convertible top dash light comes on whether or not the top opens sucesssfully. The light goes out completely just as the top goes down completely, if it goes down. After you get the top down, if you then turn the ignition off and back on, the convertible top dash light normally comes back on again (if it doesn't, I know the top won't go up..).
And the third type of faiure: oftentimes, the top begins to close normally, but then stops as soon as the top flops down onto the windshield frame. Again, I have to turn the ignition on and off while operating the rocker switch repetitively to get the top to continue to close.
I know the motor(s) that lift the top up and down are separate and apart from the motors that lock the top down onto the windshield frame just after the top flops down onto it.
Since I seem to be having a problem with both aspects of the top mechanism (the up/down thing and the lock-down thing), is there one particular wire or sensor or whatever I should be looking into that would explain all of the symptoms?
Any suggestion or info would be greatly appreciated. Even if I do let the dealer have at it, I'd like to know what is likely wrong, and what's involved in terms of parts/labor. I'm hoping my symptoms as described will prevent someone from having to dissemble and troubleshoot far flung doohickeys all over the car. I checked the fuse, #13 (I believe) in the front trunk, it was fine.
Many Thanks!
Gregory Gastman
PS I mentioned that it was a Tiptronic transmission because someone not on this list thought there was some sort of sensor/microswitch at the parking brake (but only on manual transmissions)that fails and causes a problem as the car won't let the top operate unless the motor is off AND the car was in park Or nuetral with parking brake on. I don't know if this PS info is accurate..
-top is completely open and won't close,
-top is completely closed and won't open,
-top is closing normally but then stops just as the top flops down onto the windshield frame.
Turning the ignition on and off repetitively while repetitively depressing the rocker switch that activates the top eventually does the trick, but sometimes it takes 20 minutes or several days of patience to get good results!
When the top is open and won't close, I note that the convertible top dash light does not come on when you turn the ignition on like its supposed to.
When the top is closed, and I turn on the ignition, the convertible top dash light comes on whether or not the top opens sucesssfully. The light goes out completely just as the top goes down completely, if it goes down. After you get the top down, if you then turn the ignition off and back on, the convertible top dash light normally comes back on again (if it doesn't, I know the top won't go up..).
And the third type of faiure: oftentimes, the top begins to close normally, but then stops as soon as the top flops down onto the windshield frame. Again, I have to turn the ignition on and off while operating the rocker switch repetitively to get the top to continue to close.
I know the motor(s) that lift the top up and down are separate and apart from the motors that lock the top down onto the windshield frame just after the top flops down onto it.
Since I seem to be having a problem with both aspects of the top mechanism (the up/down thing and the lock-down thing), is there one particular wire or sensor or whatever I should be looking into that would explain all of the symptoms?
Any suggestion or info would be greatly appreciated. Even if I do let the dealer have at it, I'd like to know what is likely wrong, and what's involved in terms of parts/labor. I'm hoping my symptoms as described will prevent someone from having to dissemble and troubleshoot far flung doohickeys all over the car. I checked the fuse, #13 (I believe) in the front trunk, it was fine.
Many Thanks!
Gregory Gastman
PS I mentioned that it was a Tiptronic transmission because someone not on this list thought there was some sort of sensor/microswitch at the parking brake (but only on manual transmissions)that fails and causes a problem as the car won't let the top operate unless the motor is off AND the car was in park Or nuetral with parking brake on. I don't know if this PS info is accurate..
10-23-2001, 02:54 PM
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Gregory;
Have you checked your R21 relay?
There is also a top control unit located under the left side of your dash. I would tend to think that its the control unit or a sensor. I don't think its your top motors, there are two of them, they are located behind the rear seats under the rear carpet panel. You could take them out and check them.
Have you checked your R21 relay?
There is also a top control unit located under the left side of your dash. I would tend to think that its the control unit or a sensor. I don't think its your top motors, there are two of them, they are located behind the rear seats under the rear carpet panel. You could take them out and check them.
10-24-2001, 12:10 AM
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My thanks for the responses received to date!
How does one check a relay? I honestly don't know. Relay 21; it's in the front trunk in the fuse box, right?
Does anyone have a photo or precise description/location of the control box located "under the left side of your dash"? Is it anywhere near the control box with a porsche part #(I can get it if it helps) and a VDO brand on it? That one I can see.
Can anyone provide a photo or precise description/location of the "microswitch in the passenger side rear panel"?
Many thanks!
PS: The 92 US 964 cab has no rear seats! I believe 1992 was the first year that required 3 point seatbelts in the back (or perhaps it was a tethering location change); the factory couldn't get its act together fast enough, so they simply deleted the rear seats that year!
How does one check a relay? I honestly don't know. Relay 21; it's in the front trunk in the fuse box, right?
Does anyone have a photo or precise description/location of the control box located "under the left side of your dash"? Is it anywhere near the control box with a porsche part #(I can get it if it helps) and a VDO brand on it? That one I can see.
Can anyone provide a photo or precise description/location of the "microswitch in the passenger side rear panel"?
Many thanks!
PS: The 92 US 964 cab has no rear seats! I believe 1992 was the first year that required 3 point seatbelts in the back (or perhaps it was a tethering location change); the factory couldn't get its act together fast enough, so they simply deleted the rear seats that year!
10-24-2001, 01:38 AM
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Gregory;
I have replaced a top brain in my wifes 91. I have the part number--#911 618 313 01, do you know where the central informer brain is? The top brain is stacked in the same location. If you look under the knee pad, to the left of the steering column, you will see the black box with 4 wire looms going to it. To find the micro-switch you need to pull off the passenger rear cover. You can't miss the switch. It is similar to the rear ring micro switch. Good luck.
I have replaced a top brain in my wifes 91. I have the part number--#911 618 313 01, do you know where the central informer brain is? The top brain is stacked in the same location. If you look under the knee pad, to the left of the steering column, you will see the black box with 4 wire looms going to it. To find the micro-switch you need to pull off the passenger rear cover. You can't miss the switch. It is similar to the rear ring micro switch. Good luck.
