hi,


I have a 95 r129. the hydraulic pump does not seem to be working, and I looked for voltage on the connectors to the pump, but don't see anything.
Is there an electrical diagram of where that connector is fed? which fuses should I look at?

any help would be greatly appreciated.

 

larrytbull,

checking power to the pump is easy. The pump has a 4-pin relay next to it. Read the numbers on the relay pins after you have removed the relay.

The fuse panel in the trunk has a 40A fuse that supplies power to pin 85 on the relay connector. Check first if there is power to pin 85. The relay bridges pins 85 and 87 when it is activated. If there is power to pin 85, then you could jumper pins 85 and 87 briefly, to see if the pump will run. There is a lot of current going to the pump when it starts up, so you will see some arcing on the connectors.

If the pump runs, then the next step is energizing the other two pins on the relay and seeing if it works. If both the pump and the relay are functional, which is quite likely, then the next step is finding out why the controller is not activating the relay.

Klaus

www.tophydraulicsinc.com

 

pump works,

after bridging pin 87 and 30

will check relay next

 

just tested relay, it is function as well, it is open without power then when power applied it closes 87 to 30

 

Okay, the pump works and the relay works. This means the relay is not getting the signal from the controller to turn on the pump.

Let's check out the easy things first. Since you have a model year '95, that means the windows need to be "indexed" or synchronized. This applies to model years '95-'02, where the windows have to be down a little before you close the door, so that the upper window seal does not get crushed. The windows are properly synchronized if they drop about 1/2 inch when you open the doors.

Questions: do your windows go down about 1/2 inch when you open the doors, and what position is the top in now?

Klaus

www.tophydraulicsinc.com
http://www.tophydraulicsinc.com/en/18-r129-sl-90-96

 

Yes the windows are synchronized and drop down a little when opening and closing.
Presently the hard top is on the car. I had to manually lock it in with top wrench

Roll bar will go up and down with switch. Red light on top switch flashing and it dings for a few seconds when driving

 

larrytbull,

the roll bar going up and down with the switch means that the pump and relay are good, anyway.

The chime going on when you are driving means that one of the locks is either not fully latched, or not giving the controller the latched signal. Let's deal with that first - I assume that there are other issues because you already had to put the hard top on manually.

Since you locked the hard top down manually on a '95, it might not be fully locked in the rear. '95 was a transition year, where some rear locks were delivered with the lever that allows you to lock and unlock the rear manually, and you can access them from the trunk without peeling the carpeting aside. Check out the schematic below. It shows the rear lock for the passenger side with only the short release lever, and the rear lock for the driver side with the early-model lever that allows you to lock and unlock manually (your locks would be black on a '95, even if you had the old style). Which version do you have?

 

I did not see any lever. I used the top wrench to lock, it fit on the two silver tab. Nothing looked like it could b done manually without tool

 

I am assuming from your statement that you have the newer version of lock. We can get through this a lot faster if you answer my questions directly.

While the aluminum tab ("silver" color) is made for UNlocking, it can indeed help in getting the rear locks over the dead spot near the end of travel, while pushing down the rear of the top into the lock. The pictures below show how to get access to the newer style rear locks and how to unlock them with the tool (by moving the tab upwards).

Does it feel like the rear of the hard top is locked down firmly on both sides, without play?

Klaus

www.tophydraulicsinc.com

 

I will check for that lever, didn't see it when i looked, I do however know it is down and not moving on either side
Will confirm again tonight

thanks for all the help so far

 

If the rear of the hard top is locked down tightly on both sides, then the chime probably comes from one of the front locks needing adjustment of the micro switch. You might also get away with adjusting the front prongs on the hard top back a couple of millimeters and thus making the hard top lock tighter in the front. I can provide more detail if needed.

Here is how to test the front locks:

Put the 6-mm Allen wrench in one lock and turn more in the locked position, thus taking all the play out of the lock. Holding the wrench in that position, does the chime go away? If it does, then you have found the culprit. Do the same for the other side. If one of the front lock micro switches needs adjustment, then I will provide detailed instructions.

Klaus

www.tophydraulicsinc.com

 

It looks like what you are calling a lever I am calling a silver tab, that is what i used to tighten back.

I used the wrench to tighten front and no difference when holding it as tight as it could go
still see the light on the switch

 

What about the chime - do you still hear it when you hold either front lock with the wrench and put the car in gear?

Klaus

www.tophydraulicsinc.com

 

yes i still hear the chime when in gear. even went back to check that back was ocked down as well

 

Nineteen out of twenty times, the trick I described (holding the front locks tightly in locked position) takes care of finding the problem. The chime means that one of the locks is not giving a locked signal.

Have the front locks been worked on before you started having trouble?

 

Yes the front hydraulics were replaced by the mechanic

 

Maybe it is time to take the trim panel off the windshield header and physically check that the micro switches on both sides are okay. Be careful not to damage the magnetic sensor in the middle - do not pull on its wires. See page 3 of http://www.tophydraulicsinc.com/R129...derslowres.pdf.

To compare or adjust the switches, see http://www.benzworld.org/forums/r129...-switches.html

Klaus

www.tophydraulicsinc.com

 

Hello Klaus,

I hope you're doing well sir, I am writing you today in somewhat desperate need of the assistance of a master tech with these bad boys. So my story goes like this sorry for the detail as a mechanic I find the more the better.

I had an issue where the locks in the front of my softtop unlock intermittently, I was told by the only mechanic that I could trust from reviews, and seemed to know these vehicles pretty well that it was the pump. "RIGHT AWAY as a heavy duty mechanic I could smell parts changer. However I stuck to my guns knowing that sometimes master techs know the exact point where it would be going bad. So I gave it a shot replaced the pump found one in good shape and asked them to hold the old one for me to keep for future use. I got a few other things done too at the time woodgrain steering wheel, washer fluid pump, and new instrument cluster plastic cover. Little did I know what I was getting myself into. Little off topic, but when I got the vehicle back after 3 months of waiting for the steering wheel, which was damaged from import, so after receiving the new one and it not fitting the old air bag I had to get that part from the same person who lived in Sweden. Then I get my car back late night right before closing big fear of mine is having an issue after they close. So I test drove it home and sure enough I got a flashing light on my drop top button, very audible and annoying, found my radio non functional, and my dash lights flickered when moved out of the highest setting.

Now apparently, and I know this to be true from working on very old pieces of equipment that plastic does not age well. I guess a lot of things broke while getting in there, and although they did what they could, my radio although powers on doesn't play music now, my dash needs to stay on max which is fair as he said the potentiometer carbon up everytime you use it so I imagine is worn and burnt inside, and for the convertible top apparently he DISABLED THE SYSTEM... My dread was reading all these forums and finding out the 95' and newer models did not have the ability to unlock the rear lock latches manually. I found out when my 10mm wrench spread from the effort of trying to open or close either side not a stubby but not a leverage like the real tool so wasn't sure if it was a leverage thing, and finally found some forum about how they can't be unlocked. I was quite devastated to know it has been disabled now, I called and told him and he said he didn't have as much experienceas the mechanic who left for vacation a week ago. So now I have a partially locked car, and the rain season is in here in Vancouver. It is a race against time as I have today and no rain for a few days to see if you can potentially guide me through this nightmare. As I have read about powering the pump solenoid and engaging the locks. Tried and got my pump functional from powering the relay via directly from the battery. But I'm scared to fry anything and just give power to the locks harnesses.

Now I need to know how screwed I am if I am or if I can do this. I need to know if I can actuate and unlock these latches from sending power directly from the battery to a harness and perhaps if you know which pin is the unlocking pin in the harness. Also I am on my own too so I also wanted to know if I can leave the hardtop on to do this, or if I need to get help taking it off again and exposing some relay near the roof or side or in the trunk, or find the harness and pin connector that controls those locks or if it works in conjunction with the whole system to power one after powering the other? My biggest trouble is not being able to find a service manual and now I don't want to admit defeat and take it to Mercedes where I would have to complain and tell them it should only take an hour or 2 to diagnose and get this thing locked and not get overcharged. This is my first time where I would not have the expertise to dive in or own a garage to leave it in and slowly tinker with it. I know from reading your other forums that you wanted to know how it all looks so I'll add photos and say the locks in the rear are about 3/4" from the top, and are facing toward the front and are clearly closed not allowing the latches to go further in. I do not have any power at my switch in the cab but do have a functioning pump. I need to check if there is power at the fuse maybe he just remove the pin from one side or the from the switch side. I never got to ask him but I can find out if will help. Driver side unlocking device is firm, with wrench too, passenger side I can move the metal tab up

My name is Sergio and I am really looking forward to hearing from you.

Sorry I've never been on a forum, and I wasn't sure how to find you and start my own thread, so I hope this isn't a bother how I got ahold you. Cheers.