SL/R129: Bypassing top module on 1996 500 sl?
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 15
Likes: 0
1996 sl500
Bypassing top module on 1996 500 sl?
I'm wondering if there is a relatively safe way to manually switch the control circuits on the car to raise and lower the roll bar and control the top's latches and cylinders. Who knows, maybe a person could design a better stronger control system? Thanks , Joe.
SPONSOR
Joined: Sep 2011
Posts: 475
Likes: 41
From: On the beautiful Oregon Coast
03 SL Kleemann, 97 SL320 pano top, 95 Lorinser E320 Cabrio, Ferrari 360, Tesla X
Improving the soft top controller? That's a BIG deal...
That would be a huge undertaking! Have you checked how many wires are going into the controller?
First of all, please remember that the soft top controller is a piece of safety equipment. In model years '95-'02, it controls the roll bar function. No emergency deployment without controller!
Secondly, the soft top controller also controls the windows.
There is a long, intricate sequence of events in switching the valves to operate your 11 or twelve cylinders for retraction or extension, and the controller is programmed to look for error signals coming from the micro switches, as well as signal indicating that the previous movement of another cylinder pair has been completed.
The overall design of the system is quite admirable. The controllers are a bit sensitive to voltage spikes and to immersion in water, but otherwise they hold up pretty well. What is the problem with your controller, and what are the symptoms?
Klaus
klaus@tophydraulicsinc.com
www.tophydraulicsinc.com
First of all, please remember that the soft top controller is a piece of safety equipment. In model years '95-'02, it controls the roll bar function. No emergency deployment without controller!
Secondly, the soft top controller also controls the windows.
There is a long, intricate sequence of events in switching the valves to operate your 11 or twelve cylinders for retraction or extension, and the controller is programmed to look for error signals coming from the micro switches, as well as signal indicating that the previous movement of another cylinder pair has been completed.
The overall design of the system is quite admirable. The controllers are a bit sensitive to voltage spikes and to immersion in water, but otherwise they hold up pretty well. What is the problem with your controller, and what are the symptoms?
Klaus
klaus@tophydraulicsinc.com
www.tophydraulicsinc.com
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 15
Likes: 0
1996 sl500
Thanks for responding. I agree that it is a complex system. My windows are now working properly with the auto 1/4 inch lower and raise feature and they roll up when I lock the doors. All that I did was get the motor brushes sliding freely and they work now. Like many others my top and roll bar switches stay lit and don't do anything when pressed. The previous owner said he was told by a dealership the car needs a new top module but could they diagnose this with the inoperative windows? Thanks again, Joe.
SPONSOR
Joined: Sep 2011
Posts: 475
Likes: 41
From: On the beautiful Oregon Coast
03 SL Kleemann, 97 SL320 pano top, 95 Lorinser E320 Cabrio, Ferrari 360, Tesla X
diagnosing the top hydraulic system and controller
Joe,
congrats on getting the windows to work again, and glad the Hall sensors didn't get compromised. If the windows do the 1/4" drop, then that's an excellent sign.
The controllers self-diagnose to some degree, but it's not a perfect diagnosis. It is amazing how many dealerships and high-ed shops will say the pump or the controller are bad, even if the evidence was not at all conclusive. That is not to say that a good dealership cannot be of excellent service.
Double-checking first: did they diagnose that the window motor was bad? I think Star Diagnostics should have caught that. I don't know if the controller would have given a self diagnosis of being defective when the window motor didn't work. Let's see if we can get to the bottom of this:
What are the other symptoms with your top?
Does it work in any position at all?
When did it last work, and has anything changed since then?
Is it open or closed now, and are all locks fully latched? See http://www.tophydraulicsinc.com/maunuallockhardtop.pdf for most imaginable details on latching all your locks manually.
Klaus
klaus@tophydraulicsinc.com
congrats on getting the windows to work again, and glad the Hall sensors didn't get compromised. If the windows do the 1/4" drop, then that's an excellent sign.
The controllers self-diagnose to some degree, but it's not a perfect diagnosis. It is amazing how many dealerships and high-ed shops will say the pump or the controller are bad, even if the evidence was not at all conclusive. That is not to say that a good dealership cannot be of excellent service.
Double-checking first: did they diagnose that the window motor was bad? I think Star Diagnostics should have caught that. I don't know if the controller would have given a self diagnosis of being defective when the window motor didn't work. Let's see if we can get to the bottom of this:
What are the other symptoms with your top?
Does it work in any position at all?
When did it last work, and has anything changed since then?
Is it open or closed now, and are all locks fully latched? See http://www.tophydraulicsinc.com/maunuallockhardtop.pdf for most imaginable details on latching all your locks manually.
Klaus
klaus@tophydraulicsinc.com
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 15
Likes: 0
1996 sl500
The top is currently down but I've tried it in the closed position too. When I hit the switch sometimes it blinks instead of being lit up solid red. Otherwise it's the same thing everytime I turn the ignition switch on ...... I can hear noises at the rear sounding like the top pump is running, the windshield latches make some noise too. On the topic of manually opening and closing latches sometimes I can get both sides of the rear hatch to latch and sometimes just one side. The rear window latches I've only got to latch fully once. The top fabric is too tight it seems and I plan to park it in the sunlight to stretch it enough to allow the rear and windshield latches to engage fully. Other things I should mention is that the top has never moved at all nor has the roll bar. To clear the codes I unhook the battery and I've tested the microswitches and made sure the windshield position magnet was intact. Thanks for this, Joe.
SPONSOR
Joined: Sep 2011
Posts: 475
Likes: 41
From: On the beautiful Oregon Coast
03 SL Kleemann, 97 SL320 pano top, 95 Lorinser E320 Cabrio, Ferrari 360, Tesla X
Joe,
You seem to be pretty well informed about things to look for.
With so few things working, it is a bit difficult to trace down what else might be wrong if it's NOT the controller.
I would like to give you a few hints for items to check for, before spending money on code readings with Star Diagnostics or having the controller fixed.
Two of the most common situations that freeze the soft top operation in model years '95-'02 are:
1) When the top is down, at least one of the rear locks is partially closed. The controller cannot deal with that.
2) The magnetic sensor above the windshield is broken or not in place. Page 3 of the following instructions shows how the sensor should be positioned: http://www.tophydraulicsinc.com/R129...%20Removal.pdf. To test the electrical function of the sensor, you need a multimeter and a magnet. The sensor should show a normally open circuit, and closed circuit (zero Ohms) when a magnet is near the top.
Klaus
You seem to be pretty well informed about things to look for.
With so few things working, it is a bit difficult to trace down what else might be wrong if it's NOT the controller.
I would like to give you a few hints for items to check for, before spending money on code readings with Star Diagnostics or having the controller fixed.
Two of the most common situations that freeze the soft top operation in model years '95-'02 are:
1) When the top is down, at least one of the rear locks is partially closed. The controller cannot deal with that.
2) The magnetic sensor above the windshield is broken or not in place. Page 3 of the following instructions shows how the sensor should be positioned: http://www.tophydraulicsinc.com/R129...%20Removal.pdf. To test the electrical function of the sensor, you need a multimeter and a magnet. The sensor should show a normally open circuit, and closed circuit (zero Ohms) when a magnet is near the top.
Klaus
Thread Starter
Junior Member
Joined: Sep 2011
Posts: 15
Likes: 0
1996 sl500
Since my last post I did some experiments on the car. I tested the windshield magnet switch and it works. Unless it's a coincidence the windows won't work unless the windshield latches are completely latched. If you remove the windshield panel you can see how far they have to move in order to move the microswitches. When I close the top manually I can't get them to make that final 'click' happen. I was also under the impression that the rear window couldn't be fully closed manually but it can. So now I would like to know if I should try adjusting the windshield latches so they will close manually by shimming etc or does the hydraulic system have to be working to do that? At least I could drive the car with operational windows now even if I am further delayed in getting the top module fixed. Thanks again, Joe.
