Mercedes-Benz G-Class 2012 Owners Manual - Manual (Page 236)

Position number B identifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Lift up cover : of positive terminal = in the direction of the arrow.
X Connect positive terminal = on your vehicle to positive terminal ; of donor battery B
using the jumper cable, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ? of donor battery B to earth point A of your vehicle using
the jumper cable, connecting the jumper cable to donor battery B first.
X Start the engine.
X First, remove the jumper cable from earth point A and negative terminal ?, then from
positive terminal = and positive terminal ;, each time disconnecting from the battery on
your own vehicle first.
X Have the battery checked at a qualified specialist workshop.
234
Jump-starting
Breakdown assistance