G-Class Owner's Manual - Mercedes G-Class, G-Wagon, G500, G55 ...

Practical advice
Jump-starting
The jump-starting contacts are in the engine
compartment.
1 Cover
2 Positive terminal (+)
3 Negative terminal (–)
378
P54.10-2183-31
Remove cover 1 from the positive terminal
and likewise on the donor vehicle.
Connect positive terminals 2 of both
batteries with the jump lead. Start with
the second battery.
Run the donor vehicle's engine at idling
speed.
Connect negative terminals 3 of both
batteries with the jump lead. Start with
the second battery.
Nur fuer internen Gebrauch
Start the engine.
You can now switch the electrical consumers
back on, but do not switch on
the lights.
First disconnect the jump lead from
negative terminals 3 of the batteries,
and then from positive terminals 2.
Have the battery checked at a qualified
specialist workshop, e.g. a Mercedes-
Benz Service Centre.