Battery drains when parked over night

2008 MERCEDES BENZ GL450
102,567 MILES • 4.6L • V8 • 4WD • AUTOMATIC
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MALLYBOY
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This vehicle always drain battery after driving it all day and when parked at night and in the morning you will notice that it has drain the battery. What could be likely causes to this problem, is it a faulty module or components?
Jan 17, 2022 at 1:20 AM
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ASEMASTER6371
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Good morning,

It could be almost anything.

You need to remove the negative cable from the battery and use a voltmeter in line. Red lead to the cable and black lead to the battery post.

https://www.2carpros.com/articles/car-battery-dead-overnight

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Let it sit for 15 minutes for the modules to go to sleep. Then set the meter to DC amp and read the meter. It should be50-75 milliamps only. Any more than that, you will need to start pulling fuses one by one until the draw drops to normal. That will tell you the circuit that is causing the draw.

Let me know the results.

Roy

Jan 17, 2022 at 1:49 AM
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MALLYBOY
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You need to remove the negative cable from the battery and use a voltmeter in line. Red lead to the cable and black lead to the battery post. I didn't understand it, use a picture to show me how place Red Lead to the cable and Black Lead to the battery post.. thanks for response.
Jan 17, 2022 at 3:28 PM
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ASEMASTER6371
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Did you view the guide? It shows it in detail.

Remember, you are measuring current, not voltage.

I attached a youtube video for you.

https://www.youtube.com/watch?v=KF1gijj03_0

Roy

Jan 17, 2022 at 3:35 PM
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MALLYBOY
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I do not understand the video, too much talking without showing how to set the multimeter to current scale and how to probe the multimeter lead to battery cable and negative lead to battery post, please show me with pictures how to set the multimeter to scale it will be used for the test and where to probe the positive lead of the multimeter and negative lead of the multimeter. please
Jan 19, 2022 at 12:48 AM
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ASEMASTER6371
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I will explain again.

Remove the negative cable. Take your voltmeter leads and attach the red lead to the negative cable end. Take the black lead and attach it to the negative battery post.

Set the voltmeter to DC amps and read the measurement.

Roy
Jan 19, 2022 at 3:32 AM
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MALLYBOY
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Take the black lead and attach it to the negative battery post. Do you mean Negative battery terminal or Head?
Set the voltmeter to DC amps and read the measurement. Look at the picture below and see if I set the multimeter correctly
Jan 19, 2022 at 7:52 AM
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ASEMASTER6371
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On the screen, does it say AC on the left side? Very blurry and hard to read.

Roy
Jan 19, 2022 at 7:56 AM
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MALLYBOY
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On the screen, does it say AC on the left side? It says DC on the left side and mA on bottom right of the screen.
Let me update another picture
Check and know if I set the multimeter to the scale correctly?
Jan 20, 2022 at 11:36 PM
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ASEMASTER6371
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The dial is set correctly.

Now press the range button until you see AC show up on the screen.

Roy
Jan 21, 2022 at 12:52 AM
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MALLYBOY
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Now press the range button until you see AC show up on the screen.
Has seen AC on the screen bottom left and V on bottom right of the screen.
What is the exact value that when it shows up, you will know it's good and the values that when it shows, you will know it's a problem?
Jan 21, 2022 at 11:37 AM
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ASEMASTER6371
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50 to 75 milliamps.

Roy
Jan 22, 2022 at 7:18 AM
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MALLYBOY
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50 to 75 milliamps. Okay, let me check and get back to you.
Jan 24, 2022 at 12:12 AM
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ASEMASTER6371
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Sounds like a plan.

I will be here.

Roy
Jan 24, 2022 at 3:12 AM