lddgr@yahoo.com

Battery died jumped it and it started and ran fine. Let it warm up 15 min running fine put it in reverse tires spun on snow so moved forward a bit, headlights flickered, put in reverse again stalled and died power completely gone no lights key won’t turn dead dead

cdk4219

Replace both batteries, jump starting can be costly in the long run on Mercedes, and these cars in particular. Damage the BCM and you are in for costly problems.

tonylinc

It is a bad idea to ever jump start any Mercedes. If a battery is dead I disconnect and charge, or replace the battery.
No one is ever going to jump start one of My Mercedes. Too much risk of frying electronics.
It's easy enough to disconnect a battery to recharge, and if it doesn't take a charge then replace.
If the car is stranded with a dead battery, still rather than jump start I call a tow.
Don't even ask what happened to my buddy's lawyer's perfect GL450 when he did stupid things with it against my good advice. Now he drives a Toyota. LoL
Sometimes the car is too good for the owner.

tonylinc

I hope that new batteries, or testing the "old" batteries and charging to spec, resolves your problem. Also hope that you have a good local indy shop and don't have to rely on a MB dealer to rob you blind. New trunk battery costs about $250 and I think the underhood battery costs less. When servicing or replacing batteries, be sure to follow the correct connection sequence! Please report back and let us know how it turns out.