hello, i have a 1999 c230 kompressor i just recently bought and am having issues with the battery holding a charge. when i first bought the car, it started having issues with the alarm going off at all hours of the night and turning it off with the clicker didnt work, nor did starting the car or anything else for that matter. I would drive around with the alarm going off, it was frustrating as hell. so, without wanting my neighbors to call the police or come over and shoot me, i found the fuse in box that located in the trunk and pulled it to stop the alarm. Not sure if any of this has to do with the problem i have but i thought i would mention it. anyway, now the car battery drains so i put a brand new battery in it and it drained the battery again. So, i thought for sure alternator, so i took it out to have it swapped out and the guy tested it and said alternator is working. now i am left without any knowledgeable reason for the car to not work properly, so that leads me here. I hope someone can assist me with this issue. thanks!

 

First I'm going to state the obvious, something is draining your battery. Now that we have that out of the way the next step is how to find out what may still be running or doesn't get turned off. I would suggest pulling all of the fuses one by one with all doors closed and everything shut off. Then one by one replace each fuse and listen for any device that comes on or starts up. Another method is to disconnect the negative post of your battery and put an ammeter in line to see not only if any current is flowing but how much. Then systematically remove the fuses to see which fuse has current flowing from it and look up to see which devices are on that fuse. you can then narrow it down by unplugging each device on that fuse until the current drain ceases. IE: if fuse 7 has cigarette lighter, windscreen wipers, and fog lamps, and shows current is being drained, disconnect the wipers and look at the ammeter to see if the current is still being drained.

 

I have recently purchased a 2002 c230 Kompressor that seems to be experiencing a number of the symptoms that you have described regarding eletronic failures. have you solved any or all of your problems