Owning a convertible Mercedes-Benz is fun and exciting until the convertible top stops working. If you own a hard top Mercedes convertible such as the SL-Class and SLK-Class or a soft top convertible such as the CLK / E -class and are having issues with the convertible top this article may help you.
- Mercedes Convertible Top Won’t go up or down
- Convertible top moves very slow
Common Causes of Mercedes-Benz Convertible Top Problems
Mercedes Convertible top moves very slow
- This can be caused by low fluid level or air in the hydraulic lines.
- Air in the hydrauilc lift cylinders
- It can be caused by binding of mechanical arms.
- Weak convertible top lift cylinder.
- Weak battery or ground connection.
- Leak at the o-ring at any of the lift cylinders.
- Bow tension cylinder (driver or passenger)
- Main lift cylinder (left or right)
- Tonneau cover cylinder
- Rear bow latch cylinder
- Storage cover latch cylinder
Mercedes convertible top won’t go down or raise
- Convertible top pump / motor defective
- Bad convertible top relay
- Low fluid
- Defective divider microswitch
- Transmission not in Park / Neutral
- Switch at center console is faulty
- Convertible top fluid leak
Inspect in the trunk area for hydraulic fluid leak.
Mercedes convertible deck doesn’t move
- Low fluid in the convertible top reservoir.
- Deck lid lift solenoid defective
- Deck lid micro-switch defective
- Hydraulic pump not working
- Soft top bow open/closed switch broken
- Frozen or stuck mechanical arms or broken cable
Troubleshooting Mercedes Convertible Top
- Start by pressing the convertible switch. Do the windows go down?
- If the windows don’t go down, make sure the trunk compartment divider is pulled out.
- Next, check the fuse for the convertible top. This is usally a 40 A fuse. If it is blown, replace it with a new fuse with the same ampere rating.
- Check the convertible top relay as well. Swap it with a known working relay that is identical. You can also bridge the top relay for a couple of seconds to see if the hydraulic pump start to run. Replace the convertible top relay if necessary, PN 0025421319.
- Next, check the micro switch where the divider locks. You know that trunk separator that you are supposed to pull out and engage it in this hook? It is supposed to press this little switch. Inspect it first.
You can unplug the wires going to the micro-switch. These switches should be tested for proper operation by checking continuity when the switch is pressed and when it is not. You can follow this more in depth guide on Torubleshooting Convertible Top problems.
- Check the convertible fluid reservoir. Is it below the minimum mark?
If it is below the mark, make sure to check for oil leaks at the lift cylinders.
- Add convertible fluid.
How to add convertible top fluid on a Mercedes-Benz
To add hydraulic fluid to your Mercedes-Benz convertible top reservoir you will need:
- A new syringe
- 13mm socket and ratchet
- Mercedes Convertible Top Fluid Pentosin CHF 11S Syntheitc Fluid is often used in lack of the OEM Mercedes hydrauilc fluid. Check for compatability in your owners manual.
Instructions on how to add Mercedes convertible top fluid:
- Locate the convertible top motor in the trunk. In most Mercedes-Benz cars including SL, SLK, CLK class, it is located in the trunk left or right side. You will need to remove the trunk lining to see the reservoir.
- Remove the 12mm bolt from the reservoir.
- Use a clean syringe to add fluid to the reservoir.
Hopefully, by now you have pinpointed the problem. It is possible that the convertible top operation is failing due to a problem with the N10/3 (combination control module) which is the module that controls the convertible top.
Troubleshooting Mercedes convertible problems can get very complicated and expensive. That doesn’t mean that you can’t do a few check yourself such as checking or replacing the convertible relay or adding fluid. The majority of Mercedes convertible problems are caused by a bad relay, weak lift cylinder or lift cylinder leaking by the o-ring. If you find out that the convertible top reservoir is low in fluid that means that you have a leak most likely at one of the convertible lift cylinders. It may be a very slow leak but you need to add Mercedes hydraulic fluid for the convertible top. If the fluid in the hydraulic unit gets too low, the lift cylinder may suck air and cause other symptoms such as a slow convertible top operation. Have a convertible top professional replace any lift clyinders or o-rings that may be defective.
- Mercedes-Benz Convertible Top Hydraulic Seals mbseals.com
- Mercedes Convertible Component Locations and DIY Guides tophydrauilcsinc.com
- Troubleshooting Convertible Top Problems youcanic.com
- Older convertible tops troubleshooting squarebirds.com
- Mercedes Convertible Top Operation, Electrical Schematics, Switches bayhas.com
- Mercedes Convertible Top Problem Solving Common electrical failures mbworld.org