Battery Light stays on after turning car off
11-29-2020, 12:04 PM
#1
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Mercedes Benz 240D
Battery Light stays on after turning car off
I have a 1980 240d and unless I unplug the battery from the car, the battery light stays on. If I don't unplug the battery every time I turn off the car, the battery is dead within a couple of days.
Some of the things I've tried so far:
Had the alternator replaced 3x from a local guy who works on vintage Mercedes but the battery light still turns on after turning off the car.
Tried replacing the battery and with the new battery if I keep the car connected to it, the cells in the battery died (according to the guy at the autozone) and I have to replaced the battery 2x
Used a volt reader to measure the output of the battery and it is 12.45 when is car is on, from what I've read it should be around 13 volts.
Not the most mechanically inclined but I can do basic things
I was hoping someone here has had the same issue and was able to fix it or if someone can give me some direction as to where I should look/what I should replace
Let me know if there are any more details I can provide
Some of the things I've tried so far:
Had the alternator replaced 3x from a local guy who works on vintage Mercedes but the battery light still turns on after turning off the car.
Tried replacing the battery and with the new battery if I keep the car connected to it, the cells in the battery died (according to the guy at the autozone) and I have to replaced the battery 2x
Used a volt reader to measure the output of the battery and it is 12.45 when is car is on, from what I've read it should be around 13 volts.
Not the most mechanically inclined but I can do basic things
I was hoping someone here has had the same issue and was able to fix it or if someone can give me some direction as to where I should look/what I should replace
Let me know if there are any more details I can provide
Last edited by Nimbus2000; 11-29-2020 at 12:19 PM. Reason: Edited to add more details
12-01-2020, 09:13 AM
#4
MBWorld Fanatic!
Time to google my friend...
YOu check the current draw with key out doors closed after 20 mins or so... enough time for everything to shut down.
Then you start pulling fuses and monitor the current draw... when it drops suddenly you found one circuit which is probably drawing too much and you need to investigate what is no that circuit.
Also need to know what the minimum draw should be around for your car... as it will draw something with all the computers on the cars.
YOu check the current draw with key out doors closed after 20 mins or so... enough time for everything to shut down.
Then you start pulling fuses and monitor the current draw... when it drops suddenly you found one circuit which is probably drawing too much and you need to investigate what is no that circuit.
Also need to know what the minimum draw should be around for your car... as it will draw something with all the computers on the cars.
05-23-2021, 06:34 PM
#5
"2 left right corner sagging"
Rodeo the car, I had a car sagged all the time , 15 min rodeo totaly fixed it
Lot of info from posts above about in depth battery issue , but my back to basics, get rid of that battery with a good AGM, start from a good base. S3 are rubbish anf flooded voltages and characteristics are all wrong.
I did wonder if you have a k-line issue with diags but I might be barking up the wrong tree
Rodeo the car, I had a car sagged all the time , 15 min rodeo totaly fixed it
Lot of info from posts above about in depth battery issue , but my back to basics, get rid of that battery with a good AGM, start from a good base. S3 are rubbish anf flooded voltages and characteristics are all wrong.
I did wonder if you have a k-line issue with diags but I might be barking up the wrong tree
