Motown7CLK

I want to post this as a brief FYI to W208 CLK 320 owners who may experience this issue. The convertible top on my CLK 320 stopped working last week. Just stopped after being intermittent for a few cycles (had to start and stop the car and basically kick the tires, but it finally ended up in the closed position, where I wanted it, and then it died). At the same time, my rear head rests died, as well...

I'd heard about the pump motor, and all of the other expensive parts, and when I read that the car (with +180,000 miles on it) is worth about $6000, I thought there's no way I'm paying three grand for a pump motor (no smells, no leaking fluids, etc.; it just died).

Solid repair tech spent a day and a half working on it and tested every component. Finally discovered too much resistance at one switch and realized that a wire in the harness was fraying and not getting enough juice to the motor. Fixed. total cost under $800.

If you experience a weird 'what the hell just happened to my convertible top?' problem with your CLK 320, have your repair tech consider this as part of the diagnostics.

Good luck. Still a wonderful car on a top down day driving through Napa or 17 Mile Drive in Monterey...

Ron

por2gezo

Good looking out

GatorMB

Thanks for the info,
Most of the time its a leak in the hydraulics, I read someplace that the rear bow wire harness gets frayed after much use and causes this.
All the Best, Gator

Top Hydraulics

I have dealt with customers that have had either a wire going to the rear bow lock or a wire going to the tonneau cover lock going bad.

It is a good idea always to check the fluid level in the pump first. If it is not within min/max range as marked on the reservoir, then you have a problem with a hydraulic leak. Use the first pages of this awesome DIY created by "joetwa": http://www.tophydraulicsinc.com/W208...eplacement.pdf

Motown7CLK,

thanks for posting this. I am a bit perplexed by the description. Too much resistance at one switch can be a problem. Do you know which one it was? The power going to the pump has no switch in-between, just the relay next to the pump. Could you clarify what exactly the tech has found or replaced? This could be very helpful for other forum members... :-)

While you are mentioning the pump, please allow me to elaborate a little. We rebuild lots of these pumps, and the most commonly needed part on them is a replacement electrical motor. On early W208s, the motor can simply burn out when the relay gets stuck in the closed position and keeps the motor running until it dies. We charge $600 for the rebuild with replaced motor, by the way. Mercedes-Benz does not manufacture new pumps any more; you will get a remanufactured one from them, as well.

The electric motor is actually supposed to shut off when it gets too hot. Unfortunately, that shut-off temperature seems to be set too high. We change the thermistor that senses the motor temperature to one that will make the high temp shut-off kick in a little sooner.

In any case, it is not necessarily a stuck relay that makes the electric motors fail. Some of them will simply start drawing more and more current until they finally burn out. A common sign for a motor ready to fail is that the 40A fuse keeps blowing.

Looking forward to your response,

Klaus

www.tophydraulicsinc.com

gun4hire

Any update?

I bought my car with a non-working convertible top. I have checked the hydraulic fluid level and it's at the 'max' level. rear headrests raise/lower normally. turning the convertible top handle and lifting slightly and all windows drop as designed. Then the convertible switch (normally off unless I have my lights on) just flashes repeatedly. pulling the switch and nothing happens.

All underhood fuses check out ok.

Still likely a bad motor or ?? I have not tried the manual lowering process.

GatorMB

The rear headrests are working which indicates a healthy pump, I would bet on the harness issue for the cover lock.
The rear hatch lock is hydraulic with open/close status contact. With age and repeated up/down the wires break or chafe. There are other interlock contacts as well, I would start there first.
You will have to open the top manually for an inspection and test.
Klaus is a good source for parts and direction with illustrations of the service procedure on the hydraulics.
Gator

gun4hire

One thing to add is that all four windows do not drop automatically when the convertible top is locked and the convertible switch is pulled twice then held (up or down). All fuses in the trunk also check out ok.

I'm also veering into the electrical direction...

GatorMB

When opening the lock and twisting to unlock the windows will drop,

When the top is resecured the windows can be raised by operating the top switch twice within a 2 second intreval. Its tricky the first time to get the hang of it.
The remote will close all windows as well.

Gator

gun4hire

The remote close works fine

When the top is resecured and I attempt to use the soft top switch, it will blink slowly at me.

GatorMB

Soft top This is from tho owners manual PDF, sorry about the format


165

Technical

data

Instruments

and controls

Operation


Driving Instrument

cluster display

Practical hints Car care Index

The switch is located on the center console.

Notes:

If indicator lamp blinks slowly, a malfunction has

occurred in the system.

If indicator lamp blinks rapidly, the trunk lid and/or the

luggage cover may be open, and need to be closed.

6. Lift symbol side of the soft top switch and hold:

•


The roll bar lowers (when in the upper position).

•


The soft top compartment cover and rear

window section of the soft top unlocks.

•


The rear window section of the soft top raises.

•


The soft top compartment cover opens.

•


The soft top lowers into its storage compartment.

•


The soft top compartment cover closes and

locks.

•


The indicator lamp in the soft top switch goes

out – the lowering procedure is completed – a

signal sounds.

If the soft top switch is held or is released and lifted

again within approximately 2 seconds, the side

windows will close. If the roll bar was previously in the

upper position, it will return to that position.

The side windows can also be opened/closed later on.

Lift/press soft top switch twice and hold, see page 148.

However, the side windows and the roll bar can also be

activated using their respective switches, see page 146

and page 53.
Hope this helps, Gator

GatorMB

The malfunction might be from a top control interlock contact discussed earlier

Its time to roll up the sleeves and start looking

Cheers, Gator

BK627

Don't know if you fixed the problem yet or not, but i had a similar issue and it turned out to be the relay for the convertible top. It is located I believe next to the pump. you can switch it out with the fuel pump relay (they are the same) and see if that gets your top to work.

Top Hydraulics

The CLK convertible top has only one relay, and that's indeed located next to the pump. It takes removing a number of bolt to get to it, but you can save a lot of money by checking or replacing it yourself. It is a fairly simple job, and you cannot do much damage even if you have ten thumbs. It takes some time to create the access, but that may exactly be what you don't want to pay your mechanic for...

The same DIY instructions that I referenced before for access to the pump apply for getting to the relay: http://www.tophydraulicsinc.com/W208...eplacement.pdf

The Mercedes p/n for the relay is A 002 542 13 19 aka 0025421319.

Klaus

www.tophydraulicsinc.com

Top Hydraulics

gun4hire, I second GatorMB's encouragement. You have some valuable responses to your post, and you should be able to narrow this down yourself if you are willing to work on it. Otherwise, you will be stuck paying someone else, or you might as well have purchased a coupe...

If the problem has been found already, it would be nice to let the forum know.

Klaus

www.tophydraulicsinc.com

gun4hire

My apologies for not chiming back in here. I've been putting in 50 hour work weeks and it's killing me that the top isn't working since we have had gorgeous weather.

I'm fairly good with my hands, so I'll check the relay and get back with you guys. A big thanks to all for your input.

gun4hire

Update: swapped the relay with the fuel pump relay...still no go. Ran the car with the convertible relay in place no problem...

gun4hire

After removing all the liners, it looks like the rear 'bow' lock (for the rearmost portion of the convertible top) would not release. I used a hex head to manually force it to release.

Still will not operate from that point. All wiring *appears* ok. Still troubleshooting it...

gun4hire

So top is completely folded and stored now. Trying to raise it and I get the same blinking. I would suspect a bad pump, but the headrests are working... All wiring appears ok.

gun4hire

Checked both the contact switches. Checked for continuity when open and closed and they both appear to check out.

GatorMB

The trunk circuit,
That top hydraulic pump will not run with the trunk open or if it thinks it is open.
You gave us some input earlier - The roll bars worked, We know now the hydraulic cylinder contacts are functioning.
The trunk lockdown motor must function and lock for hydraulic pump top enable.

No rush on response is not a problem for me as I work nights and writing a positive response can be a B!# sometimes.
Window circuits are going to get interesting, Find and test the trunk closed input curcit.
I will keep my eyes peeled for ya!

All the Best, Gator

gun4hire

Trunk lockdown motor? I'm not familiar with a trunk lock motor and a forum search resulted in only this thread.

The trunk door switch is working (tested by pressing the plunger in and the trunk light goes out). In the event the plunger isn't depressing all the way, I disconnected it on one side (light goes out which should simulate trunk closure) and it gives me a "fast blink" now.

The power trunk pop up motor also works.

One other note is that when trying to drop or raise the top (when I manually lowered it) an audible click could be heard from the box labelled "VDO"

gun4hire

I wish this worked properly ... she sure does look good with the top down!

GatorMB

The VDO box might be the top control module. I havent had to go this deep but will inspect mine in the daylight tommorrow. I have some radio amp work to tweak as well;
VDO is an instrument manufacturer, mostly speedo and cruise control components.

Gator
They do turn heads with the top down, Looks sharp!

gun4hire

OK, so now an update:

Drove around with the top down most of the afternoon. I get home and figure I'll give the automatic top a try. Up flipped the top panel, up came the top... I was ecstatic! Everything closed up and locked correctly.

When I tried to reopen it, it the switch just glows at me. There is a draw on the electrical since the rest of the lights dim slightly for a moment. No flashing light this time.

Think it could still be related to the rear bow lock? Maybe it's frozen somehow and not releasing the rear convertible bow? This lock would not be involved when putting the top up - only the cover lock, right?

GatorMB

There is a fix for a similar problem in the roof latch lock on this forum page, chech and see if it resembles your problem.
https://mbworld.org/forums/clk-class...hemselves.html
Cheers, Gator

current draw looks like a pump motor
Keep your wheels a spinnin and the beavers grinnin