Anyone ever have trouble with top pull down motors?

Allante North * · #1 (**permalink**) 10-14-03, 08:23 PM

Just currious if any members have ever had any problems with their rear pull down motors. I have had some problems over the last three years that I have owned mine, and I think I may have found a solution to many of the problems and a very inexpensive repair.

It seems that the switch is a two way switch and that removal of the negative input and spliceing of the two grounds will fix the problem. The pull down motor will work by using the manual switch under the rear deck lid, but not by itself. You would have to cycle the motor up and down manually, but at least it works consistantly. I know of at least three Allantes at the AAG National meet in Holly Springs that had problems, and I will try to take some pictures of what I did to correct the problem for any one that is interested.

El Dobro · #2 (**permalink**) 10-16-03, 12:01 PM

So far, I haven't had any problem with it, but I may perform a little preventive maintenance on it and lube up the worm gear to cut down friction.

Brian Bray · #3 (**permalink**) 10-17-03, 10:12 AM

I personally believe that Cadillac's adaptation of a trunk pull-down to pull down the top is somewhat lame because the top mechanism can get out of alignment very easily. We all know that the trunk pull-down has worked well for years, but the trunk is solid and can't get out of alignment whereas the top has many moving parts and the position of each can change just slightly and throw everything off.

Obviously, the J-hook and the pull-down motor need to be adjusted so that everything lines up correctly; that minimizes the wear on the entire system. Unfortunately, after a while you usually have to readjust it. Dick Hussey and others have said that their tops never get out of adjustment, so removing the ground wire or splicing the ground wires together is unnecessary, but I found that the top mechanism and J-hook, etc. on my '88 DOES get out alignment after a while and so eliminating the automatic system is much better for me. I think what you witnessed at the national meet is typical; I spent an hour in the parking lot at our local Allante gathering last year with owners who were having trouble showing them how to remove the ground wire so their top pull-down would work consistently.

I think its great that some of the pull-downs never need adjusting, but it appears to me that the vast majority of the cars would benefit by making the modification and eliminating the automatic system.

Brian Bray

Quote:

Originally Posted by Allante North *

Just currious if any members have ever had any problems with their rear pull down motors. I have had some problems over the last three years that I have owned mine, and I think I may have found a solution to many of the problems and a very inexpensive repair.

It seems that the switch is a two way switch and that removal of the negative input and spliceing of the two grounds will fix the problem. The pull down motor will work by using the manual switch under the rear deck lid, but not by itself. You would have to cycle the motor up and down manually, but at least it works consistantly. I know of at least three Allantes at the AAG National meet in Holly Springs that had problems, and I will try to take some pictures of what I did to correct the problem for any one that is interested.

jimboak · #4 (**permalink**) 10-17-03, 10:30 AM

The pulldown motor is designed to work by having the hook on the back section of the top complete the ground, starting the motor. The motor then runs until a tab on the hook hits the stop limit switch.

If the hook does not engage, the mechanism will not trip the limit switch since the tab on the hook is not pulled down. The motor will then cycle down and back up to the 'full up' position. This same function is what drives the motor up when the hook is released.

The 'manual switch' just connects the ground to start that process. If the hook is engaged, the motor should drive down, if not, it should cycle completely back to the up position, and anywhere in that cycle, the manual switch will start things going.

So if everything is adjusted right, the setup is simple and fairly foolproof.

I have seen problems occur for 2 reasons.

1- most common... the top has moved slightly and the engagement of the hook is not right. Sometimes causes the hook not to engage (top does not pull down), and sometimes causes the hook to engage but the tab on the hook misses the limit switch (top pulls down but then goes back up, or cycles continuously),.

The fix for this problem is almost always to adjust the small allen screw behind the hook to get the right alignment again, which is pretty easy to do. Do small adjustments, since if the allen screw is moved too much the hook will contact the motor when you are folding the top down, which can briefly start the motor. You then need to do a manual cycle since the mechanism will be partly retracted and the hook may not engage when the top is up.

2 - the lock and motor mechanism itself has moved, either because someone tried to force the top when the hook latch was closed, or because the mounting screws got loosened by vibration. This can cause symptoms like problem 1 but the top will not be fully pulled down when the limit switch engages (if the mounting plate is shifted up), or the top will just cycle endlessly (if the mounting plate is shifted down).

The fix is to loosen the mounting plate bolts and reposition the plate until it works correctly. This is trial and error but only takes a few minutes.

In either case, I don't think you should re-wire the top mechanism. The manual switch already will cycle the motor at any time. If the mechanism is aligned correctly, the top will latch and unlatch smoothly. If the mechasnism is not aligned, 'jumping' the ground connection just hides the problem, and allows you to latch the top without properly seating the seal with the body, which allows road noise, dirt, etc.

jimboak · #5 (**permalink**) 10-17-03, 10:44 AM

Brian - I have also met a number of Allante owners who were having trouble with the top, usually on 89 and earlier models. Still, I would advocate taking a little time to adjust the mechanism rather than disabling the auto mechanism.

For those who really don't like the Auto, I would suggest just putting an on-off switch in the ground line for the auto circuit. That way, if the mechanism screws up at an awkward time, you can flip the switch and manually pull the top down until you find a more convenient time to adjust it. You can just leave the switch in the off position if you don't mind holding the manual button every time.

But once you understand how the mechanism works, it should be reliable and trouble free with only occasional minor adjustments. I had some problems with my 91 when I first got it (and the dealer was no help at all with the top) but once I figured out how to tweak it I have had no problems in 10 years of frequent use.

Quote:

Originally Posted by Brian Bray

I personally believe that Cadillac's adaptation of a trunk pull-down to pull down the top is somewhat lame because the top mechanism can get out of alignment very easily. We all know that the trunk pull-down has worked well for years, but the trunk is solid and can't get out of alignment whereas the top has many moving parts and the position of each can change just slightly and throw everything off.

Obviously, the J-hook and the pull-down motor need to be adjusted so that everything lines up correctly; that minimizes the wear on the entire system. Unfortunately, after a while you usually have to readjust it. Dick Hussey and others have said that their tops never get out of adjustment, so removing the ground wire or splicing the ground wires together is unnecessary, but I found that the top mechanism and J-hook, etc. on my '88 DOES get out alignment after a while and so eliminating the automatic system is much better for me. I think what you witnessed at the national meet is typical; I spent an hour in the parking lot at our local Allante gathering last year with owners who were having trouble showing them how to remove the ground wire so their top pull-down would work consistently.

I think its great that some of the pull-downs never need adjusting, but it appears to me that the vast majority of the cars would benefit by making the modification and eliminating the automatic system.

Brian Bray

Stace · #6 (**permalink**) 10-18-03, 12:40 AM

I've had my '92 for three years and had several problems with the rear pull down during the first six months. I discovered that I was causing the problem by the manner I was engaging the rear pull down. I was doing it slightly off center which would eventullly cause the pull down mechnism mounts to deflect slightly. I've not had any problem in the last two and half years and I raise and lower the top every day when I park at the office.

Also, I'll reiterate the importance of the order of the steps in raising and lowering the top ... never engage or release the windshield latching motors while the rear of the top is in the down position, latched or not.

I've said before, I prefer a manual top and of all the manual tops I've had, the Allante's is my favorite ... easy, one hand operation, just picky on the sequence of steps (but a piece of cake compared to the Triumph Spitfire and MGC in years past). I'm not familiar with the Phase I tops, but I think the Phase II tops have been given a bum rap.

Stealth · #7 (**permalink**) 10-18-03, 02:07 AM

are you guys sure there is a soft top?

i been driving my '88 and i don't see a top yet ...

jimboak · #8 (**permalink**) 10-18-03, 05:09 PM

I agree on the manual top question. I can raise or lower the top in less than 10 seconds. Once I learned the drill (as you say, the sequence is important), I had no problems. Friends with hydraulic tops, or the new rage, folding hardtops, sometimes watch me fold mine and then say 'could I see that again?' since it happens so quickly. Also manual tops are much smaller and lighter weight.

I have heard enough complaints from owners of 88 and earlier Allantes that I assume there must be something to what they say, although my only direct experience with the older cars is a friend who has an 87, and he also has no problems.

Stace · #9 (**permalink**) 10-18-03, 06:40 PM

... and then there are those like Zal (Stealth) who don't even know where the top is located ...

rickko · #10 (**permalink**) 10-21-03, 07:28 PM

Here's a twist on the familiar top pull-down problem.

When I bought my '93 in April the top worked when the owner showed me how to put it up and down. When I got home and tried it, it didn't. ... Well, it *kinda* didn't.

What I mean is, it would latch but not go down right away. But somewhere in the next hour or so, the pull-down would activate and pull the top down!

Very strange!

After scratching my head awhile trying to figure out why it seemed to have this variable delay in executing the pulldown action from 5 minutes to, maybe an hour I decided to poke around with an Ohm meter.

What I found out was a loose wire connection on the motor. Once I tightened it up, its never failed to work properly again.

BTW, sometime when your playing around with your ohm meter, put the red probe on the J-hook and the black on ground somewhere nearby. You'll be surprised to see there is 12 volts running through the J-hook and all metal in contact with it. Well, that's what I found on my car anyway.... And many Allante owners seem baffled as to why their batteries are always going dead... I think one reason is in the electrical design of the top pull-down and the potenial of the J-hook or any metal in the circuit to the J-hook shorting to ground.

..rickko..

Stealth · #11 (**permalink**) 10-21-03, 07:33 PM

don't forget the trunk pull down & the power door locks ...

Quote:

Originally Posted by rickko

.............

BTW, sometime when your playing around with your ohm meter, put the red probe on the J-hook and the black on ground somewhere nearby. You'll be surprised to see there is 12 volts running through the J-hook and all metal in contact with it. Well, that's what I found on my car anyway.... And many Allante owners seem baffled as to why their batteries are always going dead... I think one reason is in the electrical design of the top pull-down and the potenial of the J-hook or any metal in the circuit to the J-hook shorting to ground.

..rickko..

jim e · #12 (**permalink**) 11-12-03, 01:27 AM

Quote:

Originally Posted by Stealth

are you guys sure there is a soft top?

i been driving my '88 and i don't see a top yet ...

Zal, when you live in central ny you know where the top is.Don't you remember what is was like here when you were here? jim

rsmith · #13 (**permalink**) 11-12-03, 07:26 PM

I purchased my 92 this past summer from the original owner, who rarely took the hardtop off, so the power latching mechanisms were never used, and the rear pull down wasn't latching correctly, though the motor did cycle. I found that a small adustment on the "J" hook combined with a small adjustment on the motor itself did the trick-it works fine now.