Hi Everyone! New here and not sure how to go about this. I recently bought a 2004 C55, always loved the car and eventually found one that was well taken care of with 100 000 kilometers on the clock, has a full service history with Mercedes, but recently I started having a dead battery in the mornings and sometimes when leaving work.

Thinking it was the battery, I replaced it, then went on a small trip where the vehicle stood for around 2 days or so before I needed to use it again. It was then when I noticed that the key I had with me stopped operating the central locking, opening and closing, and another day later the new battery was also dead.

I headed back home after a jump start and for a few days the problem continued till I booked the vehicle in with Mercedes, they had it for almost two days looking for the source that was draining the power, they came back saying it was the tracking system that was installed in the vehicle that I wasn't even aware of, I had it removed and all of this cost a small fortune, they told me they were convinced that this was the cause of my problem.

I took the vehicle home and later I noticed that the Command SatNav system was asking that I insert the SatNav DVD, but this then disappeared after one or two short trips in the vehicle.

Things were ok for a day or two after, untill I got to the car on my way home from work and again it would not start, I got a jump start and went on my way. Remembering then that the guys at Mercedes said that their equipment indicated low voltage or something on the new battery I though it could just have been from the recent drain. So I took the battery out and put it on charge for a few hours, it started fine after I reconnected it, but I now again have the SatNav asking for the disc to be inserted, while the disc is already in.

I really love the car, it's features and of course the power, not really sure what to do as it's already been quite expensive to get this sorted.

Was wondering if I could get some advice from you guys here, would be great to hear from you!

Regards to All!!!

 

I've heard of people having issues with the seat control module draining the battery...not sure what that would have to do with the sat/nav though.

My sat/nav did that for a while and now it's to the point that the nav doesn't even work anymore. I took it apart and my issue is the DVD drive is bad.

In any case, something is staying on and draining the battery power even while the car is off. OR your alternator isn't working and needs a new voltage regulator. Test the voltage drop between alternator connection and battery with a voltmeter and you should find out.

Also, try searching the forum before posting a new thread because I think people have mentioned this issue numerous times. Not trying to be an a$$hole, just giving you advice that if you post threads about something that has been discussed numerous times you will get slammed by just about every member on here.

Good luck!