2003 MERCEDES-BENZ S CLASS alternator

301 Practical hints
What to do if …?
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Possible cause
Suggested solution
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BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a battery
charger or jump started.

Have the battery checked at a ser-
vice station.
The battery is no longer charging.
Possible causes:

Alternator malfunctioning


Broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be operat-
ing with restricted capability. Considerably
greater brake pedal force is required and
the stopping distance is longer.

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz
Center.
If it is intact:

Drive immediately to the nearest au-
thorized Mercedes-Benz Center. Ad-
just driving to be consistent with
reduced braking responsiveness.

344 Practical hintsBattery
Battery
The battery is located on the right side of
the trunk under the battery cover.
1Battery cover 
Pull on the outer, right-hand side of
cover1 and remove it in the direction
of the arrow.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Center for further
information.Warning!
G
With a disconnected battery

you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button (if so equipped) on the selector
lever will have no effect


the selector lever will remain locked in
positionP

361 Technical data
Layout of poly-V-belt drive
Layout of poly-V-belt drive
S 430 / S 500
1Automatic belt tensioner
2Power steering pump
3Air conditioning compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulley
S55AMGThe S 55 AMG has two poly-V-belts (belt one
shown in purple/belt two shown in black). 1Idler pulley
2Automatic belt tensioner
3Power steering pump
4Air conditioning compressor
5Crankshaft
6Coolant pump
7Generator (alternator)
8Idler pulley
9Automatic belt tensioner
10Super charger
S600
1Automatic belt tensioner
2Power steering pump
3Air conditioning compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulley
8Idler pulley
9Idler pulley

368 Technical dataElectrical system
Electrical systemModel
S 430, S 500
S 55 AMG
S 600
Generator (alternator)
14 V / 150 A
14 V / 180 A
14 V / 180 A
Starter motor
12 V / 1.7 kW
12 V / 1.8 kW
12 V / 1.7 kW
Battery
12 V / 95 Ah
12 V / 95 Ah
12 V / 95 Ah
Spark plugs
Bosch F 8 DPP332
Beru 14 FGH 8 DPUR X 2
NGK PFR 5 R-11
NGK ILFR 6 A
NGK IFR 6 Q-G
Electrode gap
0.039 in. (1.0 mm)
0.031 in. (0.8 mm)
0.028 in. (0.7 mm)
Tightening torque
15 – 22 ft.lb. (20 – 30 Nm)
15 – 22 ft.lb. (20 – 30 Nm)
15 – 22 ft.lb. (20 – 30 Nm)

384 Technical termsMultifunction steering wheel
Steering wheel with buttons for operat-
ing the control system.
Overspeed range
Engine speeds within the red marking
of the tachometer dial. Avoid this en-
gine speed range, as it may result in se-
rious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Parktronic*
System which uses visual and acoustic
signals to assist the driver during park-
ing maneuvers.
Poly-V-belt drive
Drives engine components (alternator,
AC compressor, etc.) from the engine.Power train
Collective term designating all compo-
nents used to generate and transmit
motive power to the drive axles, includ-
ing:


Engine


Clutch/torque converter


Transmission


Transfer case


Drive shaft


Differential


Axle shafts/axles
Program mode selector switch
Used to switch the automatic transmis-
sion between standard operationS and
comfort operationC.
S 55 AMG with steering wheel gearshift
control and manual shift program: in
addition toS andC (see above), you
can useM for manual operationRemote Vehicle Diagnostics
Transmission of vehicle data and cur-
rent location to the Mercedes-Benz
Customer Assistance Center for sub-
scribers to the Tele Aid service.
REST
(Residual engine heat utilization)
Feature that uses the engine heat
stored in the coolant to heat the vehi-
cle interior for a short time after the en-
gine has been turned off.
Restraint systems
Seat belts, belt tensioners, airbags and
child restraint systems. As indepen-
dent systems, their protective func-
tions complement one another.