E320 Battery Drain
I own a 2003 E320...
I have a draw on the main battery when the car is left off overnight (Car doors will not even open in morning). We got a replacement battery with no success. Alternator tested fine, Diagonostics were run by electrical shock and has 2.2 AMP draw. Car runs absolutely fine after recharged, the only thing i've noticed is that the window functions which allow the window to go up entirely with one click (rather than holding) is disabled.
No mechanics thus far can figure out what specifically is draining the battery.
If anyone has any idea or experience with these issues any advice would be appreciated.
Thanks


Have you tried to unplug the memory seats connectors? Sometimes it is Comand, you really have to measure where the extra drain goes to.
The reason for all this is to be connected to "jumper start" by another car or "start booster" when the battery is low according to MB. Those starting methods should be avoided.
.........**Thanks**.
I own a 2003 E320...
I have a draw on the main battery when the car is left off overnight (Car doors will not even open in morning). We got a replacement battery with no success. Alternator tested fine, Diagonostics were run by electrical shock and has 2.2 AMP draw. Car runs absolutely fine after recharged, the only thing i've noticed is that the window functions which allow the window to go up entirely with one click (rather than holding) is disabled.
No mechanics thus far can figure out what specifically is draining the battery.
If anyone has any idea or experience with these issues any advice would be appreciated.
Thanks
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The problem *appears* to only happen in my garage so they are wondering if it could be a RF signal from my garage door opener or from my home that's causing the problem.
If it's a RF thing then would it be related to the Comand?
The Best of Mercedes & AMG
Possibly a short/drain on the battery. Possibly some relay stuck (that rear one in the boot by the battery?).
Currently charging the 'original' MB battery and will see if it reoccurs.
Also noticed the SBC Hold brake not working and causes ESP fault to be displayed if attempted. ESP seems ok if don't attempt to use SBC.
Need to get that looked at.
Not sure if linked to battery drain. Potentially I left parking light on or something - I had been playing with the lights.
Mike T.
Then depending on the current draw, the CD said the cause is something in a short list. As I recall for 60 mA (milliamperes) to 140 mA, it might be a trailer hitch wiring problem, a radio relay #4, or a fuse in the hat trick. Ok, maybe I don't recall the list at all but it was a list and there was a list for each range of current draws.
The CD is not great to use but it does have a load of info when you are troubleshooting and since you order through MB or at the dealer, it is legit.
I own a 2003 E320...
I have a draw on the main battery when the car is left off overnight (Car doors will not even open in morning). We got a replacement battery with no success. Alternator tested fine, Diagonostics were run by electrical shock and has 2.2 AMP draw. Car runs absolutely fine after recharged, the only thing i've noticed is that the window functions which allow the window to go up entirely with one click (rather than holding) is disabled.
No mechanics thus far can figure out what specifically is draining the battery.
If anyone has any idea or experience with these issues any advice would be appreciated.
Thanks
Mine was an aftermarket CD changer. It worked just fine but when I unplugged it, the draw ended and the battery stopped draining. If I was driving it every day, I would leave it plugged in but when I left it for a business trip, I would unplug the changer. FWIW, The car was a 1992 300TE wagon.
Good luck,
Peter
@pinoi Ryder...
any updates
any updates? I'm having the same issue I bought a new battery from advance auto a group size 49 and my battery keeps draining after 5 days .alternator is good .
Then start pulling fuses until the current flow drops. BTW, as I recall, the current flow with my problem was 240 mA and more like 20 mA without.
Peter
was the drivers seat module. I ended up buying one from Amazon for under $175. Dealer wanted $700 including diagnostic fee. A few months ago, my radio started doing random restarts when the outside temp was <55F. A few weeks ago that changed from random restarts to hearing a buzzing noise followed by the audio going out for 10-30 seconds. I also noticed that in the mornings, my battery was drained and one 2 occasions, the car wouldn't start. Yesterday I unplugged fuse #6 hoping it was the messed up radio that was causing the drain, however, my battery was dead again this morning. Tonight I'm going to test the amp pull and also disconnect the battery to see if the battery is draining on it's own. I just got the battery early last year so I doubt that's the cause but would be happy if it is, since it's still under warranty.
Does anyone have a list of what the other fuses do? And just to clarify, if I pulled fuse #6 (radio), is there anything else from the radio that would pull current from the battery?
here's a link to the seat module (drivers side) https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
i have not done the test yet for draw drain.. i will check the seat memory and remove the fuse to see if that is the cause..




