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Hey my 03 ml350 stopped charging a few nights ago. All the lights in the dash cane on started beeping and that was that. We checked the voltage regulator the alternator itself and have a brand new battery. What could be going on?? The alternator won’t charge the battery so I know it has to be something in between the two. Please help!!!! I just bought this car like 3 weeks ago
 

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Hey my 03 ml350 stopped charging a few nights ago. All the lights in the dash cane on started beeping and that was that. We checked the voltage regulator the alternator itself and have a brand new battery. What could be going on?? The alternator won’t charge the battery so I know it has to be something in between the two. Please help!!!! I just bought this car like 3 weeks ago
I dont have the same car but I figured out the problem on my c230 05' after so much money spent. The connector to the alternator(not the postive cable that goes around the nut, but the wired plastic connection had a missing gold pin inside. They are usually called "pigtails". This was keeping the alternator /battery light on. I also had previously purchased a remaufactured bosch alternator which ended up not fixing the problem.. I ended up paying for a new bosch alternator and it also helped take care of the problem.

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Thank you I will check that. Where at in the wire would it be closer to the battery or alternator. That’s the wire your talking about right
 

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Hey my 03 ml350 stopped charging a few nights ago. All the lights in the dash cane on started beeping and that was that. We checked the voltage regulator the alternator itself and have a brand new battery. What could be going on?? The alternator won’t charge the battery so I know it has to be something in between the two. Please help!!!! I just bought this car like 3 weeks ago
How did you check voltage regulator and alternator? Do you have volt meter?
 

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Discussion Starter #5
I took the alternator out and took the voltage regulator out and checked the brushes then took the alternator into a auto store and they checked it for me
 

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2003 C320 coupe, 2000 ML320
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More than likely the voltage reg. is bad... Replace it, they are fairly cheap.. If not a fix.. then move on to other common failures..
 

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2000 ML55 sold? 2013 ML500,? 2015 C250 estate wagon, 1927 Dodge 4 sedan, 1929 Dodge
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I already checked the voltage regulator and it has a lot of life left to it.
You need to check the reg while the alternator is together and spinning. It’s not something you tell just by looking at it. Your brushes may have plenty of live left in them but the reg might be toast.
How many volts did it put out at the auto store.


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2002 ML320, 2003 A160, 2002 ML500, 2018 GLS350d
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I already checked the voltage regulator and it has a lot of life left to it.
If it isn’t charging the battery, it’s dead already.

It’s not just brushes that wear out. Diodes fail, and you can’t tell by looking. The battery light is the test.

I thought bobby735 had advised you correctly. Witek_M also gave you a clue.
 
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