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I have a problem with my 2003 CLK55 AMG battery going flat when it rain. I didn't initially associate it with the rain so first replaced the battery as I didn't know how old the original was. This didn't work.
I then took it to an auto electrician and they did a diagnostic test and found a fault on the alarm sounder - this I replaced (total of £470 for diagnostic, parts, labor & vat - is that expensive?). This didn't fix the battery going flat problem - but I now have a working alarm!
If I don't use the car for 1.5 weeks with no rain and it will start fine. If it rains heavily for a few hours and I don't use the car the battery is completely flat 1 day later (I can't even open the doors). I get a jump form a starter pack and run it for an hour and the battery then works fine until the next time it rains.
Is there anything/anywhere I can check for water leakage or do I have to take it to the auto electrician again and check for current drain whilst hosing the car down! Are there any common areas affected by rain?
I have a problem with my 2003 CLK55 AMG battery going flat when it rain. I didn't initially associate it with the rain so first replaced the battery as I didn't know how old the original was. This didn't work.
I then took it to an auto electrician and they did a diagnostic test and found a fault on the alarm sounder - this I replaced (total of £470 for diagnostic, parts, labor & vat - is that expensive?). This didn't fix the battery going flat problem - but I now have a working alarm!
If I don't use the car for 1.5 weeks with no rain and it will start fine. If it rains heavily for a few hours and I don't use the car the battery is completely flat 1 day later (I can't even open the doors). I get a jump form a starter pack and run it for an hour and the battery then works fine until the next time it rains.
Is there anything/anywhere I can check for water leakage or do I have to take it to the auto electrician again and check for current drain whilst hosing the car down! Are there any common areas affected by rain?
I have a problem with my 2003 CLK55 AMG battery going flat when it rain. I didn't initially associate it with the rain so first replaced the battery as I didn't know how old the original was. This didn't work.
I then took it to an auto electrician and they did a diagnostic test and found a fault on the alarm sounder - this I replaced (total of £470 for diagnostic, parts, labor & vat - is that expensive?). This didn't fix the battery going flat problem - but I now have a working alarm!
If I don't use the car for 1.5 weeks with no rain and it will start fine. If it rains heavily for a few hours and I don't use the car the battery is completely flat 1 day later (I can't even open the doors). I get a jump form a starter pack and run it for an hour and the battery then works fine until the next time it rains.
Is there anything/anywhere I can check for water leakage or do I have to take it to the auto electrician again and check for current drain whilst hosing the car down! Are there any common areas affected by rain?
Any help appreciated.
Electrical systems can be isolated with current draw tests by fuse.
Is it a soft top? droiding now
The most likely problems associated with the symptom could be alternator regulator or ignition switch circuits failing to shut down.
Aftermarket. radio?
This faut appears to have struck my CLK55, too - did you find a solution?
As a side issue, the hood has leaked horrendously since I bought my (second-hand) 55... Initially on the passenger side, but more latterly on both. The rain is leaking in and staying stored in the soft-top roof. As soon as I go round a bend after the car has been stationary in rain for some time, I or the passenger gets a very wet sleeve! I suspect the door rubbers, but would like to confirm this before I start throwing money at it.
The water problem has just started on my car as micro-burst thunder storms dump up to 3 inches of rain in an hour or so.
With heavy rains some wheeping was evident but this year has been flood type rain.
There is a vapor barrier under the canvas that is likely getting loose with age. (suspect)
The rain puddles in there and spews while driving around the corner.
If water gets into the wrong place it can wreak havoc on electronic systems. It is best to park wise on a hill and clean up any damp carpet.
I have read another post on this from Tampa Fl but this is a new problem fo me as well.
I want to investigate this further for others as well so folllow up is inherent.
for the electrical problem have the battery load tested, (dis-connect for test @ rain), check weatherstrips under hood for sealing ECU compartment.
This faut appears to have struck my CLK55, too - did you find a solution?
As a side issue, the hood has leaked horrendously since I bought my (second-hand) 55... Initially on the passenger side, but more latterly on both. The rain is leaking in and staying stored in the soft-top roof. As soon as I go round a bend after the car has been stationary in rain for some time, I or the passenger gets a very wet sleeve! I suspect the door rubbers, but would like to confirm this before I start throwing money at it.
Thanks.
I had the same problem, garage investigated it but if anything got worse. On a whim, I decided to reproof the roof using an Auto Glym product. Bingo, no issues at all in 6 months of winter driving and the roof looks better too!
I found something that might refresh some with cab leakage.
I did some preventative maintenance on the top lubricating the hinge joints in the mechanical sections of the top. Found this:
There are nylon or canvas straps that support the barrier to the frame. Mine were broken. The cables that help to open the top also help keep the canvas tight. My drivers is broken non repairable and the passenger was missing.
We need to have a tight top with good cables, also the insulating barrier must be intact and fastened properly to prevent water from seeping through the tops mechanical joints.
CLK55 04 10K mi. battery goes flat - learned early that leaving the k owned 11 months
I learned early that leaving the key in the ignition overnight was guaranteed to kill the battery so I stopped doing it. But now the battery drains with the key out overnight. Today I drove the car 10 miles, parked it four hours, and it started right away. Stopped for fifteen minute lunch, came out, car wouldn't start. Dead battery again. Wisely I had stored jumper cables in the trunk and a very nice man helped me use them. Any ideas?
Something draining the battery that fast will be easy to find with a volt meter.
First clean the connections on a fully charged battery. Voltage 12.8 - 14
Check again in 15 minutes for a change, Remove fuses 1 by 1 until a voltage increase is noted.
Other test is with an ammeter removing fuses 1 by 1. The ammeter is connected between the battery terminal and the battery post. Observe readings.
Positive cable might hav an issue or voltage regulator does not turn off.
Thoughts,Gator
This thread doesn't include me and is another reason why I will never buy a convertible. But Gator this elec troubleshooting info is great. Thanks again for valuable information.
I take it the removal of the fuses is done when the key is removed from the ignition right? And would one conduct this series of test on all the fuses of the car not so?
05 CLK55 AMG (1 of 247) Cubanitsilber designo series
Originally Posted by fjward
I learned early that leaving the key in the ignition overnight was guaranteed to kill the battery so I stopped doing it. But now the battery drains with the key out overnight. Today I drove the car 10 miles, parked it four hours, and it started right away. Stopped for fifteen minute lunch, came out, car wouldn't start. Dead battery again. Wisely I had stored jumper cables in the trunk and a very nice man helped me use them. Any ideas?
Check the battery with a volt meter. The overnight resting voltage of a decent battery should be 12.5 - 12.8 volts. With the engine running, the voltage should be around 14.4 volts. If you see less than 14.1 volts at the battery with the engine running, it means your alternator is bad and needs to be replaced.
If you see 14.1 - 14.4 volts with the engine running, but the overnight resting voltage of the battery is below around 12.5 it means you almost certainly have one or more dead cells in your battery - it's the culprit and needs to be replaced.
Kahn - Yes perform the test with the car off and key removed from the ignition.
His symptom is that of a short in positive cabling as it drains quickly even after a cruise. To load test for dead cells like Florida Writer is explaining.
Have someone start the engine while you observe voltage across the battery, If it drops to < 10.4v consider changing the battery. One must be weary as this is the same test for a new battery and a poor starter. (noise from the starter will be evident though)
A 12 volt battery should maintain 12 volts regardless of how long it sits unused. I could not gauge the value of a battery that sits overnight and still has 12 volts without load testing. The alternator charges 13.8 - 14.1 for all cars with 12 volt batteries.
More or less could be the car or the alternator. It is a viscous circle folks.
05 CLK55 AMG (1 of 247) Cubanitsilber designo series
Not to put too fine a point on it, but all batteries self discharge, of course at different rates based on the plate material, the battery chemistry, the age of the battery and the surrounding temperature (the higher the temp the higher the self discharge rate). A brand new battery changed at 14.4 volts and taken off a charge will drop to 13 volts within a short period of time, and overnight will register "fully changed" at around 12.9 to possible 13.1 volts (any 12 volt battery whose voltage measures only 12 volts after a 24 hour rest would be considered to have at least a dead cell and certainly not healthy).
Also, there is always current draw in a modern car like the Mercedes, from the security systems to current draw to maintain the computer systems in the car. It is a minute current draw but contributes to a slow self discharge of the battery. Finally, I think the alternator voltage output in a modern Mercedes will be closer to 14.4 than 13.8 - in my CLK at idle the alternator outputs 14.4 volts which is the ideal voltage needed to change AGM and flooded batteries.
I agree, Batteries will discharge on their own to substantiate the chemical process with lead cell properties of 12 volts.
If there is any question about this measure a new battery at the local auto parts store. If you are lucky it is 12.3 to 12.6.
The drains on security and ram on logic systems are minimal to none as vehicles of the era were programmed on flash with shutdown and wake systems that use little if no inherent battery draw would inhibit starting much less no start or dead battery.
I think this thread is 2 years old but it may help a few with similar problems. Thanks for the added input and concerns, 13.8 -14.4 is for all cars and it could be fully loaded or not. It is healthy enough to keep the battery satisfied. No 2 cars will read the same.
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