electrical gremlins w209 clk convertible

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ex4x4

New Member
Joined
Oct 21, 2013
Messages
28
Location
County Durham
Car
2006 C230 se - 2004 CLK200k - 2010C180 estate - BMW X5
Hi all I'm hoping someone could point me in the right direction regarding electrical problems on my newly aquired CLK200k convertible (2004).
Bought the car last week from my local auction place - although I still paid private sale price, but such a lovely looking car inside and out I had to have it.
At the auction place I had a good look around the car and the only obvious concern was the glove box would not close ( common problem with the catch mechanism??) and the battery was completly flat. I assumed the battery was flat as the glove box light would have been on for days - draining battery.
Anyway one of the techs there connected a jump pack and it started straight away and hood opened/closed etc etc.
I won the auction and had the car delivered. I removed the battery and charged it over night, then reconnected next morning.
Battery now ok - giving 12.5 v according to instrument check feature and starts without hesitation.
Now here's the electrical concerns - hopefully all connected???

1) Although windows are now sync'ed the front windows do not drop before opening door and jam in seals. If i sit in the car with doors shut, and try to lower front windows - the rears still drop a little as they should. And when opening the roof - all windows lower as they should.

2) The central locking/ alarm will not arm - will only function if the key fob is placed directly infront of the little IR rx on door handle - but have to press either open/close numerous times for it to function. both key fob batteries have been replaced with new.

3) " display faulty - visit workshop" displayed on dash.

4 Boot will not open via fob / door card button / boot handle - will open with key blade inserted into boot lock keyhole.

5) indicators do not function from stalk or hazard switch.

6) other various buttons on dash have no function.

7) glove box light will not turn off - although the micro switch has tested healthy - the lamp will go ever so slightly dimmer when switch is closed but will not extinguish.

8) boot compartment lamp will not light.

9) over head dome light not activated by either door switch - again switch tested out of car ok.

I'm suspecting all the above maybe connected to a SAM somewhere but having a hard time trying to locate which SAM controls which function and where the SAMs are located.

Any help greatly appreciated.
 
I would still suspect the battery. 12.5 v after being on charge overnight is barely enough imo. May I suggest you check the voltage again and whilst it is displaying the voltage, turn on the headlights. I'm expecting it to drop significantly.
 
Although windows are now sync'ed the front windows do not drop before opening door and jam in seals. If i sit in the car with doors shut, and try to lower front windows - the rears still drop a little as they should. And when opening the roof - all windows lower as they should.

Normal after having a flat battery. They need to be reset
 
Congratulations on your purchase - they are lovely cars, and a bargain to boot. 


As the long time owner of a 2008 CLK 350 cabriolet I am fairly familiar with these cars. My car is rarely used so has suffered its fair share of flat batteries etc, so hopefully the information below will help. 

I would suggest: 

(1) having the battery condition checked by a garage. If it is less than 100%, get a new one fitted to rule out any issues caused by a dying battery. These cars are mega-sensitive to dying batteries. I had many of the symptoms you describe and it was all down to a duff battery. So, if money is not too tight, whack a new one in and be done with it and 100% sure the battery is fine. Or if you want to conserve your funds, get the existing battery checked and take it from there. Symptoms I had when the battery was dying on mine were: 

- analogue clock spinning round (in reverse) 
- clicking noises 
- windows not auto-closing when the doors are shut (staying open ajar) 
- boot release not working 
- all dashboard lights lit 
- steering wheel not dropping down when door closed 

You've described some of the above, so I do think the battery could be your issue. 

(2) once the battery is sorted, get a local Merc independent to reset the error codes. Your handbook will explain how to reset the window drop function etc etc. Or google. Or ask your local merc independent to reset the features for you - it takes seconds if you know what you are doing! I would also replace the battery in your remote control key fob as that could be causing further issues.  

Once that is done, you will be able to see what error codes remain. It could be a duff SAM, but equally a lot (or all of your woes) could be due to the battery.  

The good news is that the roof is working properly as these can cost £££s to fix if they are faulty. My guess, and it's only a guess, is that some or all of your issues will resolve themselves with a new battery and a trip to someone who can read the codes and reset. 

Good luck and be sure to post back with an update!
 
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wow - so much help in such a short space of time - Thankyou all for your input!!
Early this morning ( still dark early!) i set about measuring the voltage again via the on board system and my Fluke meter just to see any variation. But was suprised to see the voltage had dropped to 10.2V. arrgh.
So battery on its way out - and/or parasitic drain.
As I bought the car from auction - I have no knowledge of recent concerns with car - inc battery dying etc etc.
so new battery ordered and should arrive Wed morning.
Fingers crossed! I will post back once fitted.
Its going to be my summer car so will be stored for next few months whilst I drive my daily driver C230 .
Thanks again for all your input - I hope I can contribute at some point in the future.
 
The alarm is a known source of a parasitic drain on those and is a likely culprit.
Stuffed up behind the nearside front wheelarch cover iirc.
 
If you are planning to only drive it occasionally (like mine), get a smart trickle / maintenance charger and leave it connected all the time. Mine dies after a few weeks of no use but having it on a smart charger keeps everything fully charged and ready to go. This does assume it’s garaged I guess since leaving it on charge in the road would be tricky!
 
The alarm is a known source of a parasitic drain on those and is a likely culprit.
Stuffed up behind the nearside front wheelarch cover iirc.
Particularly if the main battery was flat and the alarm battery has now also been drained.

On the subject of batteries; I was pleasantly surprised to find that my car started immediately after having been left parked outside out house for almost four weeks whilst we were away. - There were a couple of funny noises, which have since stopped, and I had to reset the time in COMAND... but no need for the jumper pack I'd got ready.
 
Still waiting for new battery to arrive! 24hr service my @r$e.....72hrs and counting.
Hopefully tomorrow I'll be able to report back and fingers crossed it'll be good news!!
 
Fingers crossed!
 
well - still no show on the battery front - Yodel ! online tracking last updated on wednesday as "in transit" - supposed to be 24hr courier!!!:mad:
 
Probably battery is now powering the Yodel van !
 
Battery finally arrived!!!
Bench tested voltage of new battery before fitting @12.6V (low??)
Fitted to car and every circuit with which I had a concern - now worked. FANTASTIC!!!!
But short lived......
After reseting windows and testing every circuit in car I started her up and worked the roof open/close too lubricate all joints.
I then locked car via key fob.
I returned a few hours later to check something or other, but alarm fob did not work. I manually opened door via key blade and all the old concerns had returned.
Tested battery at 12.2V.
Removed battery and put on charge overnight - thinking battery had perhaps discharged whilst on shelf in store.
Next morning with a promising 12.9v charge - I reinstalled battery and once again everything worked - for a while.....
It would seem I have either recevied a duff battery - or have got a large parasitic drain.
I recharged battery again and reinstated, this time via an interuptable parrallel earth connection to allow me to place a multimeter in the circuit.
After waiting an hour or so for car to go to sleep - I have a 160ma drain - which although high-ish - shouldn't pull a new and freshly charged battery down to unacceptable levels within a couple of hours????
One thing I have noticed throughout all the testing is the red led on the alarm tow away rocker switch- is permanently flashing.......possibly duff alarm siren battery?????
I have left the battery connected tonight to check voltage again in the moring after being subjected to a night of parasitic drain.
 
I had a similar problem with my old CLK 350 several years ago after having a MB replacement battery. I left it with the dealer for several days and after testing everything all they could find was slight corrosion on the battery lead where it is attached to the body. They cleaned this, installed a new battery under warranty, didn't charge a penny, and everything was fine afterwards.
 
all they could find was slight corrosion on the battery lead where it is attached to the body

Intresting - my negative return lead has slight corrosion - the actual terminal part is plated - galv i think, and appears normal dull silver, but the exposed copper conductors appear very dull brown and oxodised and is not very flexible. Maybe another avenue to explore.
 
Well the good news is that the car is basically ok as when the battery is fully charged it all works fine. I had a feeling that would be the case. You have some kind of drain and the challenge now is to find it. Auto electrician time?
 
Auto electrician time?

I am of mixed heritage - Scotish and Yorkshire - so paying someone would go against the grain!!!!
Ill be hopefully bottoming it out myself - I like a challenge.
Tonight the alarm was going off silently, it disarmed via key fob first press and central locking opened - but then would not lock again.
The"tow away" led was still flashing once disarmed - steering me towards alarm module???
Battery removed again for charging and tested with fluke @12.2V as opposed to the dash volt check @11.9V.
I read somewhere that once the alarm module back up batteries go south, they can cause havoc with the electronics system and drain main battery.

It's my summer driver so ill just keep pluging away until I solve it. The only problem is the weather and daylight hours this time of year - plus waiting two hours to send car to "sleep" mode each time i try to test something.
Thanks to all for your valued input and Ill post up my findings as and when.
 
It does sound like a faulty alarm. Can you simply disable the alarm by removing a fuse? Or, being the alarm system, is it not as simple as that. I don’t know the answer but it feels like one of those things where you need to systematically isolate the various systems until you find the culprit. But from what you have said, the alarm is likely the issue. As Peabody said in his post....alarms are the usual culprit on these! Good luck!
 
A good point to start would be the alarm siren. They are a sealed unit and contain small batteries (soldered in place IIRC), which over time leak and create havoc with the alarm system and other electronics. You could locate it (normally in a wheel arch) and remove it/unplug it, and see if it helps cure the fault.
They are around £100 from the stealer.
 
It does sound like a faulty alarm. Can you simply disable the alarm by removing a fuse?

You could locate it (normally in a wheel arch) and remove it/unplug it, .

Looking briefly at the electrical diagrams - the siren/alarm unit is plugged into the rear SAM - so to save a bit time and effort ( jacking car - remove wheel- remove liner etc etc) I will try to locate SAM plug connection and isolate from there - if it ever stops raining.
Oh for a heated workshop with a ramp...............and a milling M/C.............and a welding bay...............and a spray booth...................................
 

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