Mercedes-Benz S 450 4MATIC Operator's Manual page 737

Practical hints
Jump starting
Remove red cover from positive
terminal 1.
Connect positive terminal 2 of the
charged battery with positive
terminal 1 of the discharged battery
with the jumper cable. Clamp cable to
charged battery 2 first.
!
Never invert the terminal connections.
Connect negative terminal 3 of
charged battery to jumper cables and
attach other end 4 to a suitable
ground point on the vehicle.
736
Get into vehicle and start engine within
30 seconds.
If the starting attempt does not suc-
ceed:
Turn the SmartKey in starter switch
to position 0.
Take out the SmartKey.
Turn off engine of donor vehicle, re-
start it and let it run at idle speed
for several minutes.
Disconnect the jumper cable during
this time.
Reconnect jumper cable as de-
scribed before.
Restart engine.
While the engine is running, switch off
several electrical consumers such as
the blower.
Disconnect jumper cables first from
ground point 4 and negative
terminal 3, then from positive
terminals 1 and 2.
Have the battery checked at the near-
est authorized Mercedes-Benz Center.