'87 Cab top won't go down

davep84 · 04-06-2010, 04:29 PM

Hi Everyone,
I just bought my first 911 recently. It's an '87 cab. I'm working through some issues with the car and one of them is that the convertible top isn't working. The red indicator light for the power top on the dash stays on all the time as well. When I press the button under the oil gauge nothing happens, but I do hear a relay or something clicking when I press it. Is there a way to just switch the car to a manual top or is there a way that I can release the top?

Thanks,
Dave

davep84 · 04-07-2010, 04:12 PM

Anyone??

kidrock · 04-07-2010, 07:55 PM

I'm still learning about my top. A lot of questions about cabriolet tops will go unanswered on this BBS...I assume it's because most everybody here has about the same amount of experience with these tops as me (basically, not much).

Did you recently purchase your cabrio? It sounds like you might have more than one issue with it. There are 2 microswitches in front near the latching mechanisms. Also, the latching mechanisms are separate motors which disconnect the top from the windshield before the main motor in the rear takes over the rest of the operation. I would probably look at those to start.

There are holes on the interior of the latching mechanism. Although I've never done this yet, I believe you can stick a regular screwdriver in those holes to actuate the latches.

A search on this website should give you a litte more info, hopefully. Good Luck.

Cattler · Cattler's Garage

It won't release at the windshield frame or it only goes partially down?

If the motors won't release, then you can use a screwdriver to manually turn the locking motors and release the catches. If the rest of your top frame is working properly, you can then lower the roof by hand. You'll likely need to use the screwdrivers again to secure the roof to the windshield frame. My experience is that this is caused by failure of the microswitches--it might also be the "brain" for the roof. This unit's located behind the passenger's side floorboard.

If it partially goes down, you might have overtightened bolts in the roof mounting area--behind the side panels in the rear seat. Just check to be sure that the roof can be lowered by moving it slowly. if you get any resistance, don't force it. Parts can crack and will cost you $$$ to replace.

I had microswitch problems when I bought my cab and later found a crack in the right main bow. Wound up replacing part of the main bow, $$ but not $$$. I also converted my power roof to manual by replacing the front locking motors with a kit consisting of targa latches and handles. Works great and its now a snap to work with the roof. Not for everyone, but I'm planning on keeping the car until it dies.

David

davep84 · 04-10-2010, 03:49 PM

Hey guys,

Thanks for the responses. My top won't release at all from the windshield, so I'll try the screwdriver thing and see if the rear motor works. I did just buy the car and was so happy with how it drove that I didn't even check the top first. Are the microswitches located inside the header rail with the release motors?

Thanks again,
Dave

kidrock · 04-11-2010, 06:14 PM

Dave,

you are correct about the location of the microswitches. Once the top is detached from the windshield frame, you will notice a plastic trigger switch on each side of the release motors. Remove the header rail to access the microswitches. Those switches are not cheap...I've seen them as low as $70 each.

You should be able to do a visual inspection of the release motors once the top has separated from the windshield frame.

davep84 · 04-13-2010, 10:50 AM

Once I released the front motors the rear one took over and folded the top down. It won't go back up at all now! I still get the same clicking from a relay under the dash when I press the top button. Is there a way to release the top from the main motor to pull it up by hand? The weather has been good here except for today, but it's starting to clear up so I can drive it with the top down. The car is much more fun that way!

Thanks again!
Dave

Cattler · Cattler's Garage

You've tried to pull it up by hand and it won't move? If that's the case, check the two large bolts in the center of the roof motor assembly behind the rear seat side quarter panels. You should loosen those--disengaging the motors from the main bow arms. Might also want to pull the fuse for the power roof until you get it sorted out.

Jeff5678 · 04-13-2010, 02:22 PM

I am having a similiar problem with my 87 Cab. The top motor will work and bring the top all the way up but it will not finish using the latching motors. I had to secure with the screw driver method. I had just had a new top installed. The top latching motors work fine to unlatch and the top will go down nice and smooth. The problem is when I put it up. Do the micro switches on the passenger side behind the rear panel need adjusting so that it tells the front latching motors it is all the way up and they should take over? I plan on trying this before I decide to take it in to the porsche dealer. Any suggestions would be very helpfull.
Thanks,
Jeff

bhoff · 04-13-2010, 02:27 PM

Sort of unrelated I also have an 87 cabro. The top works fine, however, the dash light stays on with the top fully up. It does go off when the top is down as it should. This is not a big issue because the top works ok and I just put a piece of tape over the annoying light. I did take part of the top off and I think I located all of the micro switches. No matter what switches I pushed in any combination, the light remained on. I did not know about the top "brain" so may look at this sometime. Anyone else have this situation?

davep84 · 04-13-2010, 02:44 PM

Yeah, it just doesn't want to move when I tried to pull it up by hand. I'll look for the bolts on the top motors to try and disengage them. I think the clicking noise that I'm getting when I press the top up/down switch is coming from the control box on the passenger side.

Thanks again!
Dave

911boost · 911boost's Garage

Dave, there should be two plastic plugs one on each side of the carpeted kick panel on the side of the rear seats facing inside. If you remove those, you can get access to the bolts, so that you can move the top manually. Be very carefull to not remove them too far, just loosen them. I belive that the lug wrench will even fit those bolts (I got stuck with my top halfway up once away from home).

Jeff5678 · 04-13-2010, 03:06 PM

The light will stay on if the top is not FULLY closed meaning the top latch motors do not fully latch. Try using a screw driver to finish latching the top and see if the light then goes out. I am sure it will. When I figure out my problem I am sure it will also fix yours
Jeff

davep84 · 04-13-2010, 04:51 PM

Thanks guys. I'm going to give it a try tomorrow. I hope the lug nut wrench fits since I'm out of town with the car and didn't bring any tools!

Dave

davep84 · 04-22-2010, 07:58 AM

Hi David,

Can I ask, where did you get your targa latch kit for your cab? Half the time mine will release when I want the top down and latch when I want the top up, but not always. I don't know if this would be the microswitches or the main control unit for the top.

Thanks,
Dave

viscirid · 04-22-2010, 10:39 AM

Hi Dave,
Give me a shout. I have the service and test plan manuals for our cab top, I can get you a copy.

V.

Cattler · Cattler's Garage

I got the Targa latch kit from DC Auto. Works great and a very simple install.

Jeff5678 · 05-01-2010, 11:37 AM

Well luck was with me today. As I had suspected I adjusted the micro switch for the top closing and now the latch motors kick in right as they are supposed to. All I did was adjust the micro switch so it does not make the contact until a little later. It was a couple of turns of the screw with the big washer. I am a very happy boy now....hope this might help others.
Thanks,
Jeff

Citiboy · Citiboy's Garage

My left switch is not in sync with the right side.
I've been told that a internal gear is stripped.
Do anyone know where I can buy a REBUILDING kit for the motor

ppridday · 08-19-2010, 10:42 AM

I am having a similar problem with my 88 cabrio. At first it would not do the final latching just as it was closing up. Now it does not work at all. I have purchased a new brain (off a gentleman here on the forum) and also a new locking motor. New microswitches and more. I have a factory Porsche mechanic working on it for me and he is all out of answers... He is now waiting for a 'donor' 87 or 88 cabrio to come in to try the new brain on. He did say the electrical tests he did on the new brain compared to the old one showed an open resistance on one of the resistors. Any ideas out there????

Thanks,

Paul