Just bought a 2003 e320, having issues starting.
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Joined: Aug 2020
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2003 e320
Just bought a 2003 e320, having issues starting.
Hello, I just bought a 03 e320 last week and everything has worked flawlessly until yesterday. I drove home from work yesterday at 10 PM and didnt try to drive again until about 3 pm the next day and it wouldn't start. Figured it was a dead battery so I went to go open my trunk and it wouldn't open, I also took the key out the fob and tried but it didnt turn. So i looked up how to jump without opening the trunk and long story short I followed the tutorial and jumped it from the positive that's in the fuse box under the hood. I just tried to charge enough so I could open my trunk and charge directly from the battery but my trunk still wouldn't open so I just started my car while it was hooked inside the fuse box and it started, after the car ran for a sec I was able to open my trunk but I didnt hook it up because I figured the alternator would charge it up. Well I woke up this morning to the same problem, this time jumping it from the terminal in the fuse box wont work. I tried another method which was to charge via the terminal under carpet in passenger side but that will not charge it either. My jump box says the battery charging system is weak. I'm stranded and need help.
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Joined: Oct 2016
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2012 E350 4Matic
You should take the battery in to a parts store and get it tested, it could be defective. Any idea how old the battery is, and if it's the correct one for the car?
Also, if the battery was completely dead just letting the car idle won't charge it sufficiently. It'd take a good 30 minute drive or so to get it charged back up, or use your battery charger directly connected to the battery.
You can read your battery voltage on the center cluster display by following the instructions in this video, Basically, engine off and key in position 1, and with the center display set to the speedometer press the reset button three times.
The battery voltage should be above 12v with the engine off, and somewhere around 14 with the engine running. Keeping an eye on the battery voltage while cranking and with the engine running will give you an idea of where the problem might be. If the voltage drops significantly during cranking, suspect a battery problem. If the voltage doesn't go up to 13.5-14.5 while driving, start by checking out the alternator. A really bad battery could cause the voltage to read low even if the alternator is working properly, though.
Also, if the battery was completely dead just letting the car idle won't charge it sufficiently. It'd take a good 30 minute drive or so to get it charged back up, or use your battery charger directly connected to the battery.
You can read your battery voltage on the center cluster display by following the instructions in this video, Basically, engine off and key in position 1, and with the center display set to the speedometer press the reset button three times.
The battery voltage should be above 12v with the engine off, and somewhere around 14 with the engine running. Keeping an eye on the battery voltage while cranking and with the engine running will give you an idea of where the problem might be. If the voltage drops significantly during cranking, suspect a battery problem. If the voltage doesn't go up to 13.5-14.5 while driving, start by checking out the alternator. A really bad battery could cause the voltage to read low even if the alternator is working properly, though.
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Joined: May 2017
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C320
Life pro tip: if you know you have a weak alternator or battery on a sedan, leave your rear folding seats open just in case you need to get to the battery. Inexplicably, wagons have a battery charge point under the hood and sedans don't. I'm sure it made perfect sense in German.
When you say "it wouldn't start" did it crank and not start or no crank at all? If it cranks you likely have a bad crank sensor.
When you say "it wouldn't start" did it crank and not start or no crank at all? If it cranks you likely have a bad crank sensor.
