Battery keeps dying 05 s55 amg

[Apfinfant]

Since I been having this problem I had to purchase about three batteries since then first they said it was my alternator so I got that changed still dying then I was told it was a vacuum pump got that changed also car was fine for about 3 days then battery dead again I’ve been doing a little research and from the symptoms listed I believe it’s the rear sam because I recently changed the fuel leveling position sensor and the gauge is still not working but after I changed that it started saying display Defective its says that’s a common thing when the Sam unit is bad the symptoms are taillights not working daytime running lights not working constant battery draining rear sun shade won’t come down and key not working properly.
anyone else having power draining problems

 

[alabbasi]

have you connected a multimeter to see where the draw is coming from? I suspect that a module is not going to sleep. Sometimes it's hard because you have to shut the doors to get them to do so, but there are tools to test this.

 

[markjay]

How is the battery 'dying'? Is it just going flat but can be recharged, or does it get damaged and needs replacing with new battery?

If the former, then as alabbasi said, try and identify the rogue consumer(s). If the latter, then the issue could be with the alternator, voltage regulator, or battery management module etc.

 

[Apfinfant]

How is the battery 'dying'? Is it just going flat but can be recharged, or does it get damaged and needs replacing with new battery?

If the former, then as alabbasi said, try and identify the rogue consumer(s). If the latter, then the issue could be with the alternator, voltage regulator, or battery management module etc.

Now I just keep the negative cable unplugged and trunk open a little but at first yes it was killing batterys I had to buy 3 already and they are not cheap I already replaced alternator charges battery just fine I had some one come look at it told me he the car the voltage was at like 2000w or something when it should be at around 120-180w he was only finding 2 problems which was the antenna booster for stock radio we took that fuse out then it was a vacuum pump got that changed and the battery was fine for about 3 days tried starting it in the morning battery dead again so I got a new one. Frm warranty hasn’t went dead since because I keep the negative unplugged I have a lot of rear Sam symptoms like rear visor don’t go up or down taillights don’t work daytime running lights or low beams don’t work gas gauge now working I just changed the fuel leveling position sensor and still nothing right after I did that dashboard started saying defective display which I found out has something to do with the rear Sam

 

[Apfinfant]

have you connected a multimeter to see where the draw is coming from? I suspect that a module is not going to sleep. Sometimes it's hard because you have to shut the doors to get them to do so, but there are tools to test

UPDATE
Rear Sam was toasted put the new one in today everything is working like it should be now

 

[oldguy57]

UPDATE
Rear Sam was toasted put the new one in today everything is working like it should be now

Thanks for posting the outcome, glad you got it sorted. Clearly poor diagnosis (resulting in unnecessary expense) on the part of the garage you took it to originally. Nothing beats a proper diagnosis by a mechanic who has the proper MB Star system and knows how to use it, which can save a fortune sometimes.

 

[Apfinfant]

Thanks for posting the outcome, glad you got it sorted. Clearly poor diagnosis (resulting in unnecessary expense) on the part of the garage you took it to originally. Nothing beats a proper diagnosis by a mechanic who has the proper MB Star system and knows how to use it, which can save a fortune sometimes.

Yea if I would’ve known that months ago would have saved me a lot of money