Dead battery , cant get in trunk or inside car, how to jump start? HELP!!!
Is there some power point outside the car or some way to get power to this thing to be able to open it?? Please help!!
Do I have to get a towtruck to open the door so I can get to a power point under the hood or inside the car to jump the battery?? Where are the power points to jump this car besides in the trunk?
Would calling MB roadside assistance be of any help?
Last edited by tusabes; Dec 2, 2009 at 10:45 PM.
anyway Id still like to know how to jumpstart the car from a place OTHER than the battery in the trunk...most cars with trunk batteries have a jumpstart post in the engine compartment or inside the car??
The approved solution if you have a bad battery (or a flat tire) is to call MB Roadside Assistance at 800-222-0100 (in the U.S.). For the cost of the battery, they will come to your location and replace it for you. There is no service charge, no labor charge, and the service is good for as long as the car is on the road. Two days ago I had a bad battery replaced this way, at my home, in my '78 450SL. I am not the first owner (think I'm the third), and the car is about 28 years past warranty expiration; total cost was $154 for the new battery (S-Class batteries are much more expensive) - but no other charges. The price of the MB-branded battery, by the way, was equal to or less than any other brand of battery that was made for my car.
Roadside Assistance should be able to get into the trunk using your metal key - which simply switches the latch onto or off of the central locking system.
Last edited by Skylaw; Jan 1, 2010 at 11:57 AM.
BTW - one sign of a weakening battery is strange electronic "glitches" popping up that go away after shutdown and restart, or actuating a switch. While driving on a 400 mile trip recently, I got an "ESP" warning light after turning up the volume on my radio (drawing more power). I stopped, shut down, re-started, and the light went out and stayed out without my touching the ESP switch on the dashboard. Later in the trip, waiting for passengers, I shut down the car, leaving the music on. The volume decreased slightly - not a lot, but noticeably. It came back up when I re-started. Not much doubt - that battery is beginning to go (it is 5 years old and I drive only a few days each week - a battery killer, as you'll be able to tell from the articles below).
The MB battery for the SL is lead-acid, with a silver/calcium coating on the plates. The MB S-Class battery, I am told, is an Absorptive Glass Mat (AGM) design. I don't know if it has spiral-wound plates.
I found http://batterystuff.com/knowledge-ba...=article&id=11 to be helpful in discussing battery technologies. http://batterystuff.com/knowledge-ba...n=article&id=5 gives a quick rundown on AGM vs Gel batteries. This article is also excellent, and explains the considerations in changing from one battery technology to another in your car: http://landiss.com/battery.htm - mainly, be sure your charging system is matched to the battery!
My dealer parts guy assured me that MB batteries are manufactured by MB in Germany. He said, however, that MB uses Interstate brand distributors to store and distribute batteries to MB dealers in the U.S. I believe that's a fable. Johnson Controls manufactures Interstate batteries (in fact, in the U.S. there are only 2 manufacturers - Johnson Controls and Exide - who make all the battery brands sold here). Johnson Controls also wholly owns Interstate, and manufactures batteries under the seller's specifications for other brands. My MB-branded battery is identical in appearance to an Interstate battery with the same CCA rating and size - except it has an MB sticker and part number. I am sure it was made by Johnson Controls for MB - whether in Germany or the U.S. - and is indeed sold to MB dealerships through Interstate Battery distributors. I would not have hesitated to install an Interstate branded battery in my SL. However, the price difference was zip, and MB Roadside Assistance made the whole proposition very attractive.
Last edited by Skylaw; Jan 1, 2010 at 08:09 PM.
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There is a lot more to checking a battery than checking its momentary voltage. See post #3 at http://www.benzworld.org/forums/w220...ttery-die.html for good info. It's a shame your roadside assist guy didn't use these steps.
It does pay to replace a weak battery sooner rather than later, as your experience shows.
Last edited by Skylaw; Jan 1, 2010 at 08:19 PM.
1) under the front passanger side dash where you would have your feet is the carpet right? you can actually pull the carpet back from the top and you will see styrofoam insulation, behind the insulation there is an aluminum plate, unscrew the 3-4 bolts and you will get the positive terminal..... hook it up and start your car..... in my experience thats the only way to start your car... my trunk still did not open but atleast i started the car... now how to open the trunk once the car is started????
2) under the rear right passanger there is a floor light behind which is present the fuse box of the trunk, take the fuse out, i belive it is a 20 amp yellow fuse. take it out for about 5 mins, put it back in and then try to open the trunk.... trunk will then open....
this is what i did as my vallet key wasnt even working to open the trunk, i tried WD40 and a whole lot of other things, nothing worked, i guess this was the last option... hope this helps....
1) under the front passanger side dash where you would have your feet is the carpet right? you can actually pull the carpet back from the top and you will see styrofoam insulation, behind the insulation there is an aluminum plate, unscrew the 3-4 bolts and you will get the positive terminal......
hehe, I just had to pull the carpet back so I know exactly what you are talking about... the aluminum plate with the styrooam on top. Was pretty surprised to see that!
next time I will go there for the positive terminal.
I make it a point to ensure my blade key opens the door/trunk because of this exact concern. A can of lock lube is cheap insurance once a year to make sure this lock is kept free.
And is there a way you put the pictures of that place and/or information of how to and which cables should I use to jump start. Thank you in advance.
just connect a portable jump pack , then pop the trunk.
Its still not a good idea to jump start it even if you connect the cables directly to the battery. People have FRIED their ECUs doing it.
The safest way to charge the battery at that point is to take out the battery and charge it on a charger, then reinstall it
trunk going to try your method of charging the positive terminal under the dash on passenger side my question is what do I use to ground with?

Keith


I think "no big deal. I'll just use the key to pop the trunk" NOPE...the lock cylinder is screwed too.
There is a power feed to the trunk that is easier than the footwell method. Fuse #42 in the under-hood fuse box runs right to the trunk. Remove the 20amp fuse and use a booster pack to send some power into the car. DO NOT TRY TO START THE ENGINE using this method! Just use it to pop the trunk and boost from the battery afterwards. Took me under a minute to get my car going using this method.










