Faisalgondal
New Member
- Joined
- Jun 8, 2014
- Messages
- 27
- Car
- Mercedes e250 A207 Convertible
Hi
I've been having battery drain issues with my w204 c220 CDI (2007). It's been going on for 7 months. I had a dead battery one morning (July 18) not thinking much about any electrical fault I just replaced it as it was 11 years old.
It died on me again in November 18, which was strange for a brand new battery. I took the car in to a so called auto electrician who said that there was no drain on my battery but the cells in the battery were dead so I needed to get a new one, so I ended up buying another new one.
This new battery only lasted 2 months, so I took it back to electrician who said that there was now a drain but he couldn't find the problem in 2 weeks he had my car!
So I brought it home, did a battery drain test myself with my multimeter.
Checked battery voltage, showed up as good at 12.5v. Started the car, the volts went up to 14.2v (so assuming alternator is fine)
Stopped the car, removed negative terminal and placed one end of multimeter on 10amp setting on the negative terminal of battery and the other on the negative cable that I removed. Waited for amps to settle, reading was 0.25 (250 milliamps) drain. At this point no light was on, the doors were shut and the hood was in lock position.
I then removed one fuse and relay at time to see if I get a lower reading with no luck. The amperage kept fluctuating between 100ma to 250ma.
Next I removed the seat modules one by one from driver side and passenger side, again no luck.
I then removed each bulb (head unit, glove compartment, boot), still the same result.
After a while, the reading went down to 0.02 (20miliamps) but still kept fluctuating.
What I noticed is that the once the car reaches the desired 0.01 to 0.03 (10 to 30miliamps) it stays there for a minute or so until I hear a click in the rear SAM module and then the reading jumps up to between 0.09 to 0.2) a minute later it drops back down to 0.01/0.02. I tested it like this for half an hour and the same thing kept happening. Every minute or so, the reading would jump up and then back down again.
Any help will be appreciated as my car has been off road now for a month.
Thanks
Faisal
I've been having battery drain issues with my w204 c220 CDI (2007). It's been going on for 7 months. I had a dead battery one morning (July 18) not thinking much about any electrical fault I just replaced it as it was 11 years old.
It died on me again in November 18, which was strange for a brand new battery. I took the car in to a so called auto electrician who said that there was no drain on my battery but the cells in the battery were dead so I needed to get a new one, so I ended up buying another new one.
This new battery only lasted 2 months, so I took it back to electrician who said that there was now a drain but he couldn't find the problem in 2 weeks he had my car!
So I brought it home, did a battery drain test myself with my multimeter.
Checked battery voltage, showed up as good at 12.5v. Started the car, the volts went up to 14.2v (so assuming alternator is fine)
Stopped the car, removed negative terminal and placed one end of multimeter on 10amp setting on the negative terminal of battery and the other on the negative cable that I removed. Waited for amps to settle, reading was 0.25 (250 milliamps) drain. At this point no light was on, the doors were shut and the hood was in lock position.
I then removed one fuse and relay at time to see if I get a lower reading with no luck. The amperage kept fluctuating between 100ma to 250ma.
Next I removed the seat modules one by one from driver side and passenger side, again no luck.
I then removed each bulb (head unit, glove compartment, boot), still the same result.
After a while, the reading went down to 0.02 (20miliamps) but still kept fluctuating.
What I noticed is that the once the car reaches the desired 0.01 to 0.03 (10 to 30miliamps) it stays there for a minute or so until I hear a click in the rear SAM module and then the reading jumps up to between 0.09 to 0.2) a minute later it drops back down to 0.01/0.02. I tested it like this for half an hour and the same thing kept happening. Every minute or so, the reading would jump up and then back down again.
Any help will be appreciated as my car has been off road now for a month.
Thanks
Faisal