Battery drained completely, odd electrical on E350
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2007 E350 4MATIC
Battery drained completely, odd electrical on E350
Hi Everybody,
So I have been having some odd electrical things occurring lately, and found my car battery completely drained today. It's a newer battery (replaced in last 6 months). There was a ton of water on the road last night, but these issues seem to have shown up at least a few days prior. It is getting cold here in Seattle though.
Timeline:
I do have an aftermarket head-unit connected to the car that I paid to have professionally installed ~3 years ago without significant issues (with a fiber optics adapter/connected into the main CANBUS), it's been good to me aside from losing connection with the rear backup camera about a year ago and me not being able to resolve it.
I overnighted a car charger to give the battery a charge tomorrow. I had read a similar story from somebody who ended up having a failed CANBUS adapter on their headunit, and I'm wondering if that's where I should start (just by unplugging it). Or, I get the car to somebody assuming that diagnostics would be the best approach with proper tools. What do you think?
Link to the other story: https://mbworld.org/forums/c-class-w...urned-off.html
So I have been having some odd electrical things occurring lately, and found my car battery completely drained today. It's a newer battery (replaced in last 6 months). There was a ton of water on the road last night, but these issues seem to have shown up at least a few days prior. It is getting cold here in Seattle though.
Timeline:
- Sunday: Found my trunk randomly open in my garage (I keep my car unlocked). I didn't remember leaving it open so found it odd.
- Monday Evening: Drove the car ~30 miles without issue, when I arrived my lights would not turn off in Auto mode after locking the car. I went inside, turned them off manually, and locked the car and all appeared off. After a few hours I was able to drive home without issue (car started fine and had a charge) for ~30 miles back. Once I returned, I locked my car to turn the lights off & noticed my stereo stayed on. I manually turned it off.
- Today: Went out to the car and the battery was completely drained. Lights and stereo were turned off, but something drained it.
I do have an aftermarket head-unit connected to the car that I paid to have professionally installed ~3 years ago without significant issues (with a fiber optics adapter/connected into the main CANBUS), it's been good to me aside from losing connection with the rear backup camera about a year ago and me not being able to resolve it.
I overnighted a car charger to give the battery a charge tomorrow. I had read a similar story from somebody who ended up having a failed CANBUS adapter on their headunit, and I'm wondering if that's where I should start (just by unplugging it). Or, I get the car to somebody assuming that diagnostics would be the best approach with proper tools. What do you think?
Link to the other story: https://mbworld.org/forums/c-class-w...urned-off.html
Last edited by zblowfish; Nov 8, 2022 at 09:38 PM.
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2008 E350, 2012 ML350, 2014 E350, 2015 ML350
If you have an MB-aware scanner, I would take a first look at the error codes. Since there may be a few, it is always best to take an initial note of them, clear ALL of them, and drive the car for a few miles to allow the computer to catch a few issues.
Random electrical issues can be separated to:
Good luck..
Random electrical issues can be separated to:
- Old battery not holding a charge and messing up the computers once below a certain voltage
- Be certain the battery is @12.8V when disconnected from the car, a bit lower when connected, @12.4V for a brand new battery, and the computers awake (open door for example)
- Ground connections getting loose, or corroded.
- Check for ground points, clean them up and tight them appropriately.
- Moisture/corrosion on certain modules. For example, W211 central getaway (CANBUS master) is known to corrode and mess up CANbus communication.
- Check drainage points on both corners of the windshield (read 5 below as well)
- For modified electrical wiring (as yours), all bets are off since some installers like to "be creative" and pull power from delicate modules in the Front/Rear SA
- Some installers/owners fail to close the Front SAM properly, and water intrusion in the front fuse box creates a mess of the electronics. Even worse when the clogged drainage points create a waterfall into the front fuse box.
- and the worst-case scenario: damaged parts
.
Good luck..
Last edited by JCM_MB; Nov 9, 2022 at 03:24 PM.
