07 GL450 Battery Drain Saga
Newbie
Joined: Sep 2019
Posts: 2
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2007 gl450
Battery drain
I know it may be a stupid question but could I simply replace the radio with another factory radio to eliminate the battery drain? I sat in the vehicle for an hour and heard the radio spinning at least 3 times so I’m pretty confident that the radio is draining the battery.
Newbie
Joined: Mar 2020
Posts: 6
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From: Global
GL 450 Mercedes Benz
*****I purchased this 2007 GL450 4 Matic as a Birthday gift to myself. The Previous owner has a cord running from the front to the rear as if he had an after market Amp or Kicker Box speaker connected. Car needs a jump start after leaving it off over night. Where do I start the trouble shooting process? Has anyone had this issue with my year make and model?*****
Newbie
Joined: Mar 2020
Posts: 6
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From: Global
GL 450 Mercedes Benz
Have any of you with power drains related to the COMAND interface (DVD, NAV, Radio etc) checked for stuck buttons?
A constant key push signal may keep the central gateway from shutting off all but keep alive power when the key is removed and the driver's door is closed.
Haven't tested this but it's an easy enough troubleshooting step - press every button and check for stuck or binding action. Slinging coffee and kids yoghurt around the cabin will usually do that.
A constant key push signal may keep the central gateway from shutting off all but keep alive power when the key is removed and the driver's door is closed.
Haven't tested this but it's an easy enough troubleshooting step - press every button and check for stuck or binding action. Slinging coffee and kids yoghurt around the cabin will usually do that.
Newbie
Joined: Mar 2020
Posts: 6
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From: Global
GL 450 Mercedes Benz
So, wake up one morning, no advance warning ie sluggish battery previously and dead in the water. Jump it, run it considerably throughout the day. Dead again next morning. Assume battery has reached end of useful life. (it was a recently purchased used 07 GL with about 80K on it, had one previously from new, went to ML 2011 and quickly came back to my first Benz love)
Take a look at battery and hmmm - appears to have been replaced once already. So - really shouldn't need a new yet I would think. Take to parts store, test battery, appears fine according to conductive load test. now what?
Turn off all electrical convenience features, give it a good charge (but it never seems to want to get to full charge according to charger amp draw) Only have 2A and 10A charger settings and have heard you don't want to put more than 8A charge on these AGM batteries so go with 2A setting and start paying attention. Seem to hear RSE DVD spinning endlessly after key off. 10-15 minutes - then finally seems to go off but I continue to hear the Nav DVD doing a familiar disc access read clicking, that never stops. Turn everything off, have left off comand for days, step out of car in garage, shut door, leave window open so I can hear without having to open the door. Come back hours later. Disc access noises continues every 10 secs or so you can hear it doing something. Removed NAV DVD (it was HOT) with power off. Then you can still here is attempting to see if DVD still in the player. clunk......clunk and a little 'tink' in between from somewhere in the back (thinking the RSE)
This all seemed to start after setting Command to Rear and AUX settings when attempting to hook up ipod to RSE Aux inputs to listen to over speakers. (Never did get that to work) Remote for RSE seems to have few buttons that actually work.
With electrical features off, it's starting but some mornings barely. I just dont want to dump in a new battery unless I know I don't have a key off drain somewhere.
But - finally my question - any reason this device should continue to attempt to read and access the NAV DVD endlessly after key off. If I pull the fuse, will I not have other necessary functionality for driving. (don't care about loss of nav locations saves etc. haven't that many) But do care if I have to go and get something reset - reloaded etc once power is lost to CC. I wanted to leave fuse out for day or two and see if perceived battery drain issue ends. Don't have tools for accurate AMP draw test at key off. (Well I do have a very old volt, ohm, in line Amp meter) But according to this, at 11.8 to 12.1ish V my battery should be completely dead?!
Wondering if anyone has had any similar experiences. Next step key off draw test with and without Radio fuse in place I guess.... also wanted to verify fuse 25 (Radio) and should I pull fuse 23 for RSE at the same time?
Spent a lot of time looking for other posts on subject. All you folks are great I have to say.
Thanks for any advice that can be provided.
FYI - I have been experiencing a few other strange electricals. directional headlamps that want to go out for a few seconds after corner returns (right only) not certain if related or not.
Love the GL! (but after a lot of research here wondering if I might be on borrowed time for some pretty expensive repairs shortly.....suspension, struts, etc.)
Take a look at battery and hmmm - appears to have been replaced once already. So - really shouldn't need a new yet I would think. Take to parts store, test battery, appears fine according to conductive load test. now what?
Turn off all electrical convenience features, give it a good charge (but it never seems to want to get to full charge according to charger amp draw) Only have 2A and 10A charger settings and have heard you don't want to put more than 8A charge on these AGM batteries so go with 2A setting and start paying attention. Seem to hear RSE DVD spinning endlessly after key off. 10-15 minutes - then finally seems to go off but I continue to hear the Nav DVD doing a familiar disc access read clicking, that never stops. Turn everything off, have left off comand for days, step out of car in garage, shut door, leave window open so I can hear without having to open the door. Come back hours later. Disc access noises continues every 10 secs or so you can hear it doing something. Removed NAV DVD (it was HOT) with power off. Then you can still here is attempting to see if DVD still in the player. clunk......clunk and a little 'tink' in between from somewhere in the back (thinking the RSE)
This all seemed to start after setting Command to Rear and AUX settings when attempting to hook up ipod to RSE Aux inputs to listen to over speakers. (Never did get that to work) Remote for RSE seems to have few buttons that actually work.
With electrical features off, it's starting but some mornings barely. I just dont want to dump in a new battery unless I know I don't have a key off drain somewhere.
But - finally my question - any reason this device should continue to attempt to read and access the NAV DVD endlessly after key off. If I pull the fuse, will I not have other necessary functionality for driving. (don't care about loss of nav locations saves etc. haven't that many) But do care if I have to go and get something reset - reloaded etc once power is lost to CC. I wanted to leave fuse out for day or two and see if perceived battery drain issue ends. Don't have tools for accurate AMP draw test at key off. (Well I do have a very old volt, ohm, in line Amp meter) But according to this, at 11.8 to 12.1ish V my battery should be completely dead?!
Wondering if anyone has had any similar experiences. Next step key off draw test with and without Radio fuse in place I guess.... also wanted to verify fuse 25 (Radio) and should I pull fuse 23 for RSE at the same time?
Spent a lot of time looking for other posts on subject. All you folks are great I have to say.
Thanks for any advice that can be provided.
FYI - I have been experiencing a few other strange electricals. directional headlamps that want to go out for a few seconds after corner returns (right only) not certain if related or not.
Love the GL! (but after a lot of research here wondering if I might be on borrowed time for some pretty expensive repairs shortly.....suspension, struts, etc.)
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
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From: Allentown, PA
'08 GL 320 CDI
Beezalino - you only need to ask the question once! 
Start with some of the suggestions presented above (read through every response) and then let us know what you've done. Otherwise, we may just be repeating ourselves for no good reason. Once we have more info, we can help better.
What does this "cord" connect to (on both ends)?
Start with some of the suggestions presented above (read through every response) and then let us know what you've done. Otherwise, we may just be repeating ourselves for no good reason. Once we have more info, we can help better.
What does this "cord" connect to (on both ends)?
Newbie
Joined: Dec 2024
Posts: 1
Likes: 1
Fuse 25 culprit
Has anyone figured out the draining source from fuse 25? I have the exact same problem with my battery dying. As soon as I figured out it was fuse 25 and I removed it I haven’t had a problem since. But I would love to have a radio and back up camera again!
2008 GL450
2008 GL450
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
Has anyone figured out the draining source from fuse 25? I have the exact same problem with my battery dying. As soon as I figured out it was fuse 25 and I removed it I haven’t had a problem since. But I would love to have a radio and back up camera again!
2008 GL450
2008 GL450
Junior Member
Joined: Dec 2024
Posts: 20
Likes: 1
Happy holidays from Sweden!
Super thankful for this thread - have spent the last days in my GL350 to find the source of battery drain, bought a new amp clamp yesterday when I found this thread and right now I’m in the car since 2h..
Have had multiple weird problems with the car over the last six months - battery, SRS, Airmatic, ABS etc, and I’m pretty sure all is because of the low battery from parasite drain..
Found that fuse 23 & 25 solves most of it - I could hear front CD tray being activated every minute or so previously.
Before removing fuse 23 & 25 I had a constant drainage of about 6-7 amp. Now after removing fuses it’s shifting between 2 amp and 0,4 amp (400mA) every other second. Been doing that for an hour and goes into the same mode after unlocking/locking and waiting until it shuts down. Car closed and locked.
Any ideas why it’s still shifting between 400mA and 2 amps? Have tried removing/measured most of the back right fuses, but still the same.
The exact rotation is about five seconds and looks like this: 2,0 - 1,5 - 0,4 amp —> repeat
Would be very thankful for any kind of input!
Super thankful for this thread - have spent the last days in my GL350 to find the source of battery drain, bought a new amp clamp yesterday when I found this thread and right now I’m in the car since 2h..
Have had multiple weird problems with the car over the last six months - battery, SRS, Airmatic, ABS etc, and I’m pretty sure all is because of the low battery from parasite drain..
Found that fuse 23 & 25 solves most of it - I could hear front CD tray being activated every minute or so previously.
Before removing fuse 23 & 25 I had a constant drainage of about 6-7 amp. Now after removing fuses it’s shifting between 2 amp and 0,4 amp (400mA) every other second. Been doing that for an hour and goes into the same mode after unlocking/locking and waiting until it shuts down. Car closed and locked.
Any ideas why it’s still shifting between 400mA and 2 amps? Have tried removing/measured most of the back right fuses, but still the same.
The exact rotation is about five seconds and looks like this: 2,0 - 1,5 - 0,4 amp —> repeat
Would be very thankful for any kind of input!
Last edited by GL350_Sweden; Dec 21, 2024 at 06:34 PM.
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Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
have double checked all the discs are ejected? Including the navigation? Just incase you have a jambed disk
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Joined: Dec 2024
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And yes, I’ve tried to check that all CD’s are ejected but if there’s one stuck, how would I know?
Senior Member
Joined: Oct 2015
Posts: 397
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From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
don’t forget when you turn power on after battery disconnect it will do a grind through the magazine to see which ones are full
Junior Member
Joined: Dec 2024
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Any ideas what could cause the 400mA <> 2 amp drain?
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
all I can think is to check both sams. Rear Beside spare tyre well on right under fuse box (pull out spare and see if water). Other is under front right seat in your model. The GL leaks in water from sunroof. Tail light seals rear windows and the plastic moonroof. Good luck
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Joined: Dec 2024
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Update to future readers: Parasitic drain problem seems to be completely solved now after removing fuses 23/25 overnight and then inserting 6 retro discs in the CD changer after installing fuses again.
Not sure if removing and putting back the fuses solved it or filling up the shuttle with some 90’s soul and rock, but give both a try! (don’t try pop or metal)
Will update if problem comes back again, if not I guess this solved it long term!
Not sure if removing and putting back the fuses solved it or filling up the shuttle with some 90’s soul and rock, but give both a try! (don’t try pop or metal)
Will update if problem comes back again, if not I guess this solved it long term!
Last edited by GL350_Sweden; Dec 22, 2024 at 10:10 AM.
Junior Member
Joined: Dec 2024
Posts: 20
Likes: 1
Update to future readers: Parasitic drain problem seems to be completely solved now after removing fuses 23/25 overnight and then inserting 6 retro discs in the CD changer after installing fuses again.
Will update if problem comes back again, if not I guess this solved it long term!
Will update if problem comes back again, if not I guess this solved it long term!
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Joined: Aug 2003
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From: In my garage
E55, GLS450, GL63, GLE350
all I can think is to check both sams. Rear Beside spare tyre well on right under fuse box (pull out spare and see if water). Other is under front right seat in your model. The GL leaks in water from sunroof. Tail light seals rear windows and the plastic moonroof. Good luck
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
there is plenty of room in the centre console behind the aircon controls etc to have the relays.
the early 164 was easy to change radio units from a wreck (as long as the car you got the unit from had the same or more features) but I think after the 08 update that was not possible
Last edited by wannawagon; Dec 28, 2024 at 03:57 PM.
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Joined: Dec 2024
Posts: 20
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I've already bridged the relays over the two rear fuses—works great for fixing the battery drain issue. However, the radio now starts with a buzz, loses its memory, and has no saved channels. Planning to physically remove the CD changer—anyone know how? It's the version where all discs are inserted into the COMAND unit, not the glovebox.
