S-Class (W221) 2007-2013: S 320 CDI, S 350, S 450, S 500, S 550, S 420 CDI, S 600

Battery Question

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Old Nov 15, 2022 | 01:31 PM
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V12Kid's Avatar
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Battery Question

I have a 2009 and today my car wont start. The dash is dim and the starter wont turn over.

is this the front battery or the rear one? I am unsure which to change

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Old Nov 15, 2022 | 06:13 PM
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2007 S600, 2007 Chrysler 300 SRT8, 2000 C5 Corvette, 2017 Mustang GT, 2023 300C, and a 2019 Lincoln
Check the voltage on the starter battery in the front. It is used to start the car only. The rear battery is much larger and supports all the electrical needs of the car.

If your starter battery upfront does not show 12.0 volts, try a charger. It is also possible that your alternator is not putting out enough juice to keep that starter battery fresh. Once she starts, the starter battery should show a slow return to 14.0 volts or more. You might charge the starter battery fully, and then take a voltage measurement the following morning. You should still have 12.0 volts from that battery.

Please measure and report back what you find.
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Old Dec 7, 2022 | 07:10 PM
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@V12Kid - did you fix the issue? What was it?
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Old Dec 7, 2022 | 07:50 PM
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Originally Posted by Jason B
@V12Kid - did you fix the issue? What was it?
Ended up being the battery and the starter lol.

I was able to replace the battery myself but my local shop replaced the starter. Good to go now
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Old Dec 8, 2022 | 01:56 AM
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Nice to see it was that easy to fix it
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