Power Convertible Top Won't Close

Adidas · 06-09-2009, 01:00 PM

I've got a 93 911 convertible. The power top will not completely close most of the time when I depress the rocker switch. I have to lift up on it to raise it an couple inches above the windshield frame and drop it lightly a few times before the locking motors engage. The top once seated in appears to be level and straight and I don't feel any binding at all before the motors start to engage. Is this a switch/relay/ or other problem. Thanks in advance. Bill

krd · 06-09-2009, 02:45 PM

check yours switches on the top of the windshield

diverdan · diverdan's Garage

From your post, I am sot sure if the top alignment is correct. It should drop in by itself. Its a tricky adjustment that's is easy enough to get at by removing the rear seat the side panels. The switches are little micro switches that are in the top header. These can break or the springs can come off. They are activated when the top header pushes them against the top of the windshield frame. If you have had trouble with the top lifting at high speed their is a chance that the gear on the latch motor may have fractured and not hold tight enough on the shaft which could lead to the problem described. Good luck.

Dan

kidrock · 06-10-2009, 10:54 AM

+1 with diverdan, it sounds like your top is out of alignment...particularly where the front of the top connects to the windshield.

I have an '88 cab, so I'm unfamiliar with the vagaries of the '93 cab...so for the sake of argument, I'll assume they are similar.

If you have 2 latching mechanisms at the front of the top, each latch on the headliner/windshield should have 2 adjustment screws. Additionally, there are 2 "prongs"...1 on each side of the top, which center themselves into a set of receiving holes that are located on the far ends of the windshield. These prongs and holes are also adjustable, and may be the source of your problem.

If you feel comfortable enough to take a stab at it, you could raise and lower the top as you make adjustments back and forth until you achieve the best fit.

Adidas · 06-11-2009, 02:27 PM

I took a closer look and here is what I know.
1. Both microswithes on the front top header panel are adjusted to extend as far as possible to make sure they both are compressed. The springs feel good and tight on both units.
2. The top alighntment seems to be very close. When I let the top drop in by hand it almost completely falls all the way in. The drivers side is just a hair off and when I barely move the top alittle on this end it falls in.
3. I pulled both of the long finger like prongs out and repositioned them with no difference.
4. This car had previously suffered the dreaded beakage of the frame and 1 arm on each side has been removed which takes the 2 rear transmissions out of the picture. Basically I just push the rocker switch to lift the top out of the windshield frame and then manually take it back from there. Putting the top back on is the same thing. Manuallly I pull the top up by hand and let it lightly rest in the plastic receiving pockets on the windshield frame, then I push the rocker switch and then nothing usually happens at all until I try multiple times.
5. Something else that I tried was to lift the top up off the header frame and hold both microswitches in all the way with my hands with someone else pushing the rocker switch and nothing happens as well. What doesn't make sense to me is that the front motors LIFT the top every single time with no problem, I just have a problem with them retracting the top back in. After 10 to 12 times continiously pushing the switch it finally seats down. Could this be the rocker switch wearing out or is there a brain or big relay somewhere that could be failing. I can check the alignment again if this could be the problem
When the front motors finally engage the top pulls down tight and very even. Any help appreciated. Bill

kidrock · 06-11-2009, 07:13 PM

sounds beyond my limited expertise, I apologize.

Just a guess (or 2). First, I'd be concerned about the previous damage. It's within the realm of possibility that the extent of the damage makes it near impossible to get a proper adjustment.

Another possibility is the tops are controlled by cables on either side, I believe. I know very little about these cables, but maybe one of these cables is disconnected or loose, and could use tightening, adjustment or replacement. Without a proper shop manual with diagrams, it could be a situation where you may need to start probing around start eliminating possible culprits.

good luck............

Jeff5678 · 04-17-2010, 02:31 PM

Adidas,
I have the exact same problem with my 87 cab. I just had the top replaced and now the problem exists. The frame and everything else is in great condition and it lines up great. I would love to hear if you find out what causes this. I will do the same after I play with it some more.
Thanks,
Jeff

Cattler · Cattler's Garage

+1 on the last post. I had a cracked right main bow very ckose to the "B" pillar top. After replacing with a used bow half its structurally sound but seemed skewed a bit. I also have to pull the roof down to ensure proper alignment. Helped to replace a few seals to ensure water and wind tightness. This is probably something you'll need to get used to and can't fix perfectly.

David

glennspiegler · glennspiegler's Garage

This happened to me. The relays and circuit board in the black box under the passenger side floor had several solder in the board that had cracked, the way they do in the cruise control. Was making intermitant contact. Three quick joint solders and it works fine. You have to look at the back of the board in the black box. Glenn

bell · bell's Garage

i have recently fixed a few similar problems......
take a close look at the gearboxes on each side (the motor is behind the rear seat, they are cable driven), see if they move at all when you raise/lower the top, in 2 instances the mounting bolts were stripped or loose which would cause the micro switches to activate prematurely and they wouldn't close or it would twist......
once the motors are mounted securely you need to readjust the large threaded rods below the motors to adjust the stop height/alignment before it latches to the top of the windshield.
also check that both sides are moving (possible broken drive cables?)

Jeff5678 · 04-20-2010, 04:17 PM

glennspiegler ,
I was looking at the "black box" unfortunately there are 4 of them on the floor behind the passenger seat. Which one controls the top? Do you have a picture of them and which one it would be? My Cruise control also does not work right. When I activate it the speed increases constantly...and very quickly..like I masjhed the pedal to the floor. It never lets up. I have to hit the brake pedal to kick it out. Thoughts? Suggestions?
Thanks,
Jeff