Ml jump start question - urgent - PeachParts Mercedes-Benz Forum

lkchris · #1 10-13-2008, 12:48 PM

Jump starting is thoroughly explained in the Owners Manual.

acapulco36 · #2 10-13-2008, 03:17 PM

Kent,

Thanks for the reply. My owners manuel got ripped off some where along the
way. If you or anyone else can give me a quick synop of the procedure as
lad out in the manuel it will be appreciated.

I am going to have to deal with it on Thursday ( 10/16 )
afternoon once I get to my place there.

The vehicle has been sitting since 7/27, so it will be about 2 1/2 mths. Battery was strong < normal > when I parked it.

Anyone had experience with how long the MB batteries last when parked.

I know they are quite big and if the only draw down is the clock I could be ok ... Though it has been the rainy season there, so quite moist & humid.

Of course I will post the out come.

But any info length of time or longest anyone else has gone between starts
would be nice to know.

Thanks

sunedog · #3 10-13-2008, 05:08 PM

My dad taught me many years ago....

positive to positive, negative to GROUND

Really should be in that order.

I borrowed most of the following from this site http://autorepair.about.com/cs/doityourself/a/bljumpstart.htm

1. Attach one end of one cable to the dead battery's positive terminal.

2. Attach the other end of the same cable to the positive terminal of the battery in the starting vehicle.

3. Attach one end of the other cable to the negative terminal of the battery in the starting vehicle.

4. Attach the other end of that cable to the engine block of the car with the dead battery. (The reason not to attach final connection directly to the battery is that the last connection will produce a small spark. Explosive gasses come out of batteries. Don't want to ignite them with the spark.)

Reverse the order precisely to disengage.

Gilly · #4 10-13-2008, 06:26 PM

I can see where a completly dead battery could cause a few concerns. When you manually unlock the truck (which is never a really "good" thing to do NORMALLY, unless the key has a dead battery or the vehicle battery is dead), I believe you may get the alarm going off AND the engine disabled, as the AAM may assume the truck has been broken in to, once you hook up the jumpers. SO, be ready to lock/unlock the truck with the remote key. You should also make sure the key is inserted into the ignition AFTER there is battery power, as once again the imobillizer won't be active until after there is some battery voltage present. So in effect, what I want you to do, is assuming the truck is dead (no unlocking with the remote), go ahead and manually unlock the door. Then pop the hood, and hook up the jumper cables (if you want to try starting it before jumping, fine, but then remove the key from the ignition). Hook up the cables and anticipate the alarm will go off, you can then do a lock/unlock with the remote. Then you put the key in the ignition and the truck should start fine.
Gilly

DUTCH · #5 10-13-2008, 07:07 PM

If you want to be a little safer, turn off the engine on the jumper car before connecting the jumper cables. Use the jumper car's battery by itself (no engine running) to start your car. That way you don't have the over charging voltage surging into your dead system with the potential of frying something.

The attached scan is from the 2007 ML Owner's Manual. Later on in the instructions, it does say to start the engine of the donor vehicle and have it running at idle; but only after connecting the positive terminals only. The negative cable is attached after the donor engine is idling.

Personally, if I were afraid of frying something, I'd use the donor's battery without the engine running.