07 battery issues
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2005 S430
07 battery issues
Hello. Can someone please help me? My 07’s main battery only work when the car is started. About 10 seconds after turning off the car it looses all power. I tested both batteries and the alternator and they passed.
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2010 E550, 273 Engine: 2012 S550, 278 Engine
So, when you say your battery loses all power does it start ok next time you try to start it? If it does your battery does not lose all power, if it did the car would not star again.
Perhaps someone changed the time the car is alive after it is shut down and nothing is wrong? You need to keep key in ACC position to run radio without the engine running...?
Last edited by Arrie; Jul 16, 2025 at 12:07 AM.
Thread Starter
Junior Member
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2005 S430
The car starts right up the next time. After turning off the car I have about 10 seconds to get out and turn on the alarm before all power is lost. I have to use the actual key to to unlock the car. Turning the key to ACC does nothing. When i start the car the instrument panel comes on and the clock adjusts it time
Senior Member
Joined: Mar 2018
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2006 W221 S500L M273
Sounds like a problem with the big battery in the trunk.
How did you test it?
You can also loosen the wire terminals to the big battery in the trunk from the junction box near the small (starter) battery under the hood and test it from there too. Do not just test voltage, you want a big load on it to test the wiring (resistance).
How did you test it?
You can also loosen the wire terminals to the big battery in the trunk from the junction box near the small (starter) battery under the hood and test it from there too. Do not just test voltage, you want a big load on it to test the wiring (resistance).
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2007 S600, 2007 Chrysler 300 SRT8, 2000 C5 Corvette, 2017 Mustang GT, 2023 300C, and a 2019 Lincoln
How old is the consumer battery in the trunk? If it is older than 7 years, just replace it. Usually a battery will have a date code on it.
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Junior Member
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2005 S430
Originally Posted by vettebk;[url=tel:9189354
9189354[/url]]How old is the consumer battery in the trunk? If it is older than 7 years, just replace it. Usually a battery will have a date code on it.
