GLBnzMan

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.)

GLBnzMan

Oh - one additional fact. Car running output seems fine. 13.5-14V range depending on accessory load. So don't believe that is the issues....

BenzMan and enjoying it. (so far)

uncleshim

Did you ever find the root cause?

I bought an 07 GL450 just 6 months ago with 50k miles on it and just last night it started having the exact issues you explain. I also have instrument cluster munitions selling me that there is a taillight out or front directional which is not the case when I check the bulbs.
Is this the price paid for buying a first model year vehicle?

Hope you can help shed some light on your experience finding the solution.
Thanks!
Tim

Kropf

I'm a recent GL owner...
Upon arriving at the selling dealership that had already replaced the battery, an aftermarket alternator, and then a Mercedes alternator, the 2007 GL450 was 'dead as a doornail'. The dealer jumped it. We ran it while completing the paperwork and then immediately drove it on the leading edge of a winter storm to Ohio. It started fine the next day as we visited family, but then it sat for most of the third day as we waited for the northeast to recover from the Feb 1 storm. I went to it late that third day, and it was completely dead again. Onto the forums that night and read about the rear latch problems. I went out to the GL and sure enough, the rear door latch was stuck in the squeezed/'open' position. I pushed the latch back, and after AAA jumped it the next morning, it's been fine since! (We just make sure that the latch moves back to the un-squeezed position. I notice that it only seems to stick if the door has road dirt. When the GL is clean, it doesn't seem to stick.)

P.S. It got worse over the years - even when the GL was very clean.

(I've heard the Navigation DVD spinning up at odd times, but I haven't given it much further thought.)

Check your rear door/hatch latch to be sure it's not stuck in the squeezed/open position that appears to completely drain the battery.

================================================== ================================================== ====
Edit 10/30/2023:

After 8 years of simply pushing the latch back to avoid a drained battery, I had the inner Rear Door/Hatch cover off, and choose to fix the sticky latch. Here's a photo of the corrosion on the shaft that caused it to bind:


The corrosion on the shaft was wire-wheeled off, then lubed the shaft before re-inserting.

Reassembled (notice the original spring clip pushed back onto the end of the shaft):


Wow! A simple squeeze and release and saved the $70~ replacement price. - No more drained battery from that problem!

bha

GLBnzMan, did you ever get this resolved? What was the fix?

I am having the exact same problem. 2007 GL320, recently new original MB battery, car started dying when parked overnight. It will barely go 12 hours of being parked before it is too dead to start.

Charging battery up fully allows it to start and drive. Lots of driving is fine, just can't park it overnight.

Have tried disconnecting the liftgate fuse (problem still exists) and have updated rear SAM software according to the MB TSB

Yesterday when I was in the car with a mostly dead battery (it was on the charger, charging at the time) I heard the HVAC blower fan try to start up, shut off, then repeat again a few seconds later.. keeps happening probably because there is barely enough juice in the battery. This was all with the ignition in the 'on; position (all dashboard lights on)

But then I heard something weird..rear DVD was trying to spin up too! Rear entertainment system is completely off so no reason for that DVD to run at all

I pulled fuse 23 and 25 and am waiting 12-24 hrs to see if that fixes it.

Did either of those fuses fix your problem? Which one? I have heard the audio gateway in these cars can be a problem too, and it is likely powered by one of those fuses along with the rear DVD.

Hoping it's the rear DVD since a)it is mechanical and can easily be the source of the problem, b)I never use it and don't care if it is disconnected, c)it is easy to disconnect, and d)I am all out of other ideas

DennisG01

BHA... from your post, it sounds like the issue started happening AFTER you got the new battery? If so, charge it completely and then get it load tested. The problem could be as simple as a bad battery. And, when the voltage is low, all kinds of weird things start happening. Until you first verify the battery is good, I wouldn't do anything else - start at the beginning, otherwise you might just be trying to chase your tail. 'Course, if pulling the fuse for the DVD solves the problem, then you're good!

bha

No, sorry if I explained it wrong. Battery was replaced about a year ago. I was just making the point that the battery wasn't old, and also that it is an original OEM MB battery from the dealer.

The GL worked fine for about a year after replacing the battery. Even now with the battery drain problems I can charge it up perfectly and drive, it's just that it dies overnight. Alternator tested and it is putting out proper voltage (14.5v) when running.

If I charge it up now, I can drive it 1000 miles without a problem, even making multiple stops and shutting it off. But if I leave it overnight it will be dead. It definitely sounds like some kind of parasitic draw is going on.

My next step is to pull fuses one by one and watch the current, to see if I can figure out what circuit. Was just hoping it was the DVD or Audio Gateway.

DennisG01

OK, gotcha. If you have no luck with pulling the fuse for the DVD, I'd still start with a load test. The reason you can drive as long as you want (even making some short stops) is because your alternator is working and keeping the battery topped off. Making sure the battery is properly good is a excellent first step.

Now, the other thing you can do is an amp draw test - you can google that if you don't know what it is (although it sounds like that's your plan?)... but essentially you're disconnecting the battery lead and hooking your DMM between the battery cable and battery post. Then, you let computer "go to sleep" (I'm not sure exactly how long it is for this car, but 1/2 hour should suffice) after turning everything off. Then check how many amps you see - it SHOULD be less than an amp or so. If it's higher, then start pulling fuses to find the suspect circuit. Note... during this time, don't open/close any doors or turn anything on as it will wake up the computer.

bha

Yes, that is exactly my plan.

I have done a quick amp test (MB says leave the car off for 35 mins to let everything go to sleep) a few weeks ago, and I remember getting a reading of over 3000ma (3 amps) of drain with everything off. I moved onto looking at other things, but will be trying the full test again this weekend (including pulling fuses one by one)

That makes sense because if the battery is almost 100ah then at a rate of 3amps per hour, it would drain down to about 25% in 24 hours. That's close enough to the drain I'm seeing so I'm sure this 3amp drain is the problem.

Just need to find out what is causing it!

Also an update with some good news..I let the car sit for about 24 hours the other day and it dropped from 12.x volts to 11.2 (or 11.1 can't remember) while sitting. Wouldn't start.

I pulled fuses 23 & 25 yesterday to see if the rear DVD (known to be on these fuses) or Audio Gateway (not sure but assume it is on one of these fuses) was the cause of the problem.

After 12 hours was down to 11.9v. After another 4hrs (total 16hrs) it is still at 11.9v and seems to have stopped dropping.

I'll see if the truck start tonight at 11.9v but that seems low to me. Good news is that the drain is much less than before.. will still need to do a parasitic load test but this seems like good news so far. I'll leave it a full 24h and measure the voltage but I expect it will stay at 11.9v now.

Miguk_Saram

I recently had a similar problem: battery would drain over night.

My 2 cents:

I looked into parasitic drains as well, but the Amp output at rest was around .05 amps - well within tolerance.

Over a period of about a week I tried jump starting the car and driving on the highway for 30-45 minutes to get it back to charge, but the problem continued. I decided to pull the battery and noticed a bit of a bulge (not a good sign). I opened her up and noticed that she was quite low on fluid, so I topped her off with some distilled water and trickle charged for about 36 hrs - problem solved. The GL has been starting fine since.

You could also try swapping the batteries with one of your other vehicles' known-good-battery to 1) see if this resolves the problem, or 2) see if the problem carries over to the other vehicle. Both of these scenarios would indicate a faulty battery.

DennisG01

Let's hope you found the excessive draw that easily! Then, let's hope you can get the battery charged back to a proper level and it stays there. A new battery is usually around 12.8V. Once a battery gets below 12.5V, it's pretty much on it's way out.

bha

I may be getting close to a solution

So it turns out that pulling fuse 23 and 25 solved the problem (or at least most of it). I waited 24 hours and was able to start the truck (it died in 12 hrs and wasn't startable by that point). Cranked and started first try. I left it another 8-9 hours (32 hrs total) and it started again also.

So the problem is definitely fuse 23/25

23 is the rear DVD and 25 is the comand/radio/etc

I'm going to put 25 back in today and try to unplug the rear DVD player so I can put fuse 23 back in. I'll drive it today (and have fully charged the battery) and leave it overnight and see tomorrow whether it starts.

I'm 90% sure it's the DVD player. If not I'll have to start diagnosing the stuff that's on fuse 25. Fuse 23 is only the DVD and nothing else is on that circuit. Fuse 25 has a few things including radio, probably an audio gateway, etc

DennisG01

Hopefully it's the DVD!

bha

Getting closer....

Pulled Fuse 23 which contains the DVD player and no problems with battery dying. So it is definitely a problem w/something on the Fuse 23 circuit

Disconnected DVD from harness and plugged Fuse 23 back in. Battery died overnight!

So it's not the DVD

From the wiring diagrams, it seems there are 3 things on Fuse 23:

1. Rear DVD player
2. CTEL module located under the rear seat (drivers side). From pics, it looks easy to unplug. Not sure I can leave it unplugged as without Fuse 23 there is no audio in the truck (radio works but no sound). So I suspect this item needs power and needs to work, otherwise I need to get a MOST jumper and bypass it entirely. If I unplug it I think I'm going to have no audio in the truck. I can get a used one of these under $100 on eBay so maybe that's an option too. Let's see if this is the problem first though. The blutooth puck in the armrest also doesn't light up so it seems to be receiving power from this CTEL unit also.
3. Rear Entertainment controller under the drivers seat (some labour to get to it, as the seat has to come out).

Remember I have an aftermarket stereo so don't actually need this item at all (stereo has BT built in, and I no longer have the rear entertainment system hooked up). So if I can unplug/bypass that's fine with me!

I'm going to try #2 next, then look at #3. I'll hook up the ammeter to ground cable of battery (disconnected) and look for changes in parasitic draw as I disconnect stuff)

For now the good news is my wife can drive the truck and not get stranded. Just no audio from the audio system, but otherwise the truck performs completely normally!

Khadari7

I'm dying to know if you solved this problem BHA. My 2008 GL450 worked fine until I tried to access the aux connection through the rear DVD. Now I continually have the same drain problem (even after replacing the ECU under the hood, with the matching Gateway, EIS, key faub, and a new battery twice in one week.) The first replacement battery wouldn't take a charge.

The Faub is working fine. the Gateway is registering when I run the scan with my iCarsoft MB II. Everything else seems to be registering as well. No aftermarket parts inside my GL. High output brake lights though. I've had issues with the SRS weight sensor under the front passenger seat, due to a weak plug, but that's not the issue.

Please help!!!

Khadari7

DenniesG01,
Did you ever get a solution to the power drain?

bha

So just an update for everyone on this...

I was chasing down Fuse 23 because removing 23 and 25 fixed the problem. Battery kept dying.

Bought a Lisle parasitic drain tester (goes between the negative battery post and negative battery cable, and your voltmeter plugs into it. Allows easy connection of the voltmeter. Left the right rear door open but latched it shut using a screw driver, so the car thinks it's shut. Locked the car and left it in garage for 35+ mins, so everything went to sleep.

Started pulling fuses. When I got to Fuse 25, the drain on the battery went away completely (ie. from 3200ma down to under 100ma. I think it was actually around 20 ma to be exact). So this fuse was the problem.

Left Fuse 25 out and reconnected everything and drove the truck around to recharge it fully. Then locked the truck and went on vacation for 2 weeks. When I came back it started without a problem!

So definitely an issue with Fuse 25. I'm investigating and disconnecting things one at a time to see what fixes the problem. I have pulled the communication units under the rear left seat (I believe one is CTEL and the other is Teleaid?) and those didn't fix it. So I'll continue disconnecting stuff, but mostly on this fuse it is bluetooth etc.

The only thing I really need on this fuse is the radio. Without F25 in, the radio doesn't power up.

So I also have a plan b. If nothing else on this fuse is useful to me (I have a radio with Bluetooth built in and don't need that, I don't use the iPod connection and I don't have a TeleAid subscription), then I can leave it out of the fusebox without a problem.

I am thinking of pulling the cigarette lighter out from under the passenger footwell and wiring the radio to that for power. Then I'll have the radio on a separate switched power connection, and everything else on F25 can stay unpowered without an issue. I'll have my radio back an no more battery drain!

Radio is only a month old but the battery drain started a few months before it was installed. So I am reasonably certain that the radio isn't the issue (problem started before it was ever installed) and also it is brand new so shouldn't be causing a problem.

May also consider looking at the iPod interface kit because I once saw the iPod on with the car powered off a few months ago which seems odd to me. It isn't integral to the car (separately installed MB accessory) so it can be easily unplugged as it is just a T-harness behind the radio. I might unplug it to see if that fixes the issue while I have the radio out, before I connect radio power to the cigarette lighter.

So for anyone having an issue, try Fuse 25. But the easiest way is to get a Lisle 64970 test lead set from Amazon and hook up your meter to it. Makes it way easier to troubleshoot this. Yes you can hook up your meter directly but this includes a bypass switch and alligator clamps large enough for battery terminals and cables. It's really difficult to rig up your meter leads and then try to secure them onto the battery properly. The kit just plugs in to your meter and connects up easily. Then start pulling fuses till you see the problem and leave the offending fuse out for a few days!

Max Blast

"Remember I have an aftermarket stereo"

In the world of strange electrical problems, that statement right there covers 80% of the root causes.

I know you stated that the drain began before you put in an aftermarket stereo.

But - these things rarely just start happening own their own unless someone monkeys with something electrical.

Khadari7

bha, thanks for your update. I thinkI have the drain under control now, but I'm still not getting any response from the starter. I'm going to do a manual test on it today. I hate to sound like an idiot, but I haven't done that yet. The starter never gave me any sign or indication that it was less than reliable. Now it seems as though I need to find another specific thread for THIS issue.

eric_in_sd

Holy moly! 3.2A quiescent drain! Did the thing keep your garage warm?!?
That's either a terrible aftermarket radio or it's installed wrong - or is defective. Even installed right, it would be draining 3.2A while you drive around. That's like 5% of your alternator output. (I'm guessing the alternator amperage, recalling 55A at points in my past. Pls no hate, guise.)
Every car stereo needs a "clock" power, which is always on, and usually is connected to a "Acc" power, meaning it comes on with the ignition switch in accessory position. Still, with the stereo off, no way should it be draining 3.2A.
Do you have a secondary amplifier installed? It might have that static drain level. However, the thing will get hot, as it's burning ~40W. That's legit a fire hazard if it's covered in carpeting.
Sounds to me like your installation was bungled, or the unit is defective.

Edit: Whoops, didn't catch that the drain started before the radio was installed. Think real careful about that; if true, you've got issues somewhere you need to track down. Like I said, 40W is going somewhere, and concentrated it will easily melt fuse blocks or whatever it's near. I'd be hoping it's the radio because that will be easier to track down.

eric_in_sd

Weak starter can mimic battery failure and leakage. As the starter spins slower and weaker it draws more current. Also has to crank for longer because there seems to be a circuit that prevents fuel delivery unless engine rpm is above a certain level. Those two compound to result in fast battery drain. I changed my starter and my battery problems promptly disappeared.

DennisG01

Khadari - I was not the one with the power drain issue.

machadosl

I hada a problem like this in my 2007 GL500, the battery was out in about 4 days. The problem was the original radio in permanent stand by mode, that I disabled it entering in the engineering mode.

2007gl

How did you change the radio to engineering mode?

Max Blast

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.