MERCEDES-BENZ R320 2008 W251 Owner's Manual

480 Practical hints
Replacing bulbs
Bulbs
Safe vehicle operation depends on proper
exterior lighting and signaling. It is there-
fore essential that all bulbs and lamp
assemblies are in good working order at
all times.
Correct headlamp adjustment is extremely
important. Have headlamps checked and
readjusted at regular intervals and when a
bulb has been replaced. Contact an autho-
rized Mercedes-Benz Light Truck Center
for headlamp adjustment.iIf the headlamps or front fog lamps are
fogged up on the inside as a result of high humid-
ity, driving the vehicle a distance with the lights
on should clear up the fogging.iSubstitute bulbs will be brought into use
when the following lamps malfunction:

Turn signal lamps

Brake lamps

Parking lamps

Tail lamps
Read and observe messages in the multifunction
display (
page 455).

481 Practical hints
Replacing bulbs
Front lampsRear lamps
LampType
1Parking/standing lampW 5 W
2Turn signal lampPY 21 W
3Additional turn signal
lamp
LED
4Headlamps:
Low beam
H7 (55 W)
Bi-Xenon headlamps*:
Low beam1D2S-35 W
5Headlamps:
High beam/high beam
flasher
H7 (55 W)
Bi-Xenon headlamps*:
High beam/high beam
flasher spot lamp
H7 (55 W)
6Side marker lampWY 5 W
7Front fog lampH7 (55 W)
Corner-illuminating
front fog lamp*
H7 (55 W)
1Vehicles with Bi-Xenon* headlamps: Do not
replace the Bi-Xenon bulbs yourself. Contact an
authorized Mercedes-Benz Light Truck Center.
LampType
LampType
8High-mounted brake
lamp
LED
9Tail, brake, and side
marker lamp
P 21 W
aTurn signal lampPY 21 W
bBackup lampP 21 W
cRear fog lamp (driver’s
side only)
P 21 W
dLicense plate lampsC 5 W

482 Practical hints
Replacing bulbs
Notes on bulb replacement

Only use 12-volt bulbs of the same type
and with the specified watt rating.

Switch the lights off before changing a
bulb to prevent short circuits.

Always use a clean lint-free cloth when
handling bulbs.

Your hands should be dry and free of oil
and grease.

If the newly installed bulb does not
come on, contact an authorized
Mercedes-Benz Light Truck Center.Have the LEDs and bulbs for the following
lamps replaced by an authorized
Mercedes-Benz Light Truck Center:

the additional turn signal lamps in the
exterior rear view mirrors

the high mounted brake lamp

the Bi-Xenon* low beam lamps

the Bi-Xenon* high beam flasher spot-
light

the front side marker lamps
Warning!G
Bulbs and bulb sockets can be very hot.
Allow the lamp to cool down before chang-
ing a bulb.
Keep bulbs out of reach of children.
Halogen lamps contain pressurized gas.
A bulb can explode if you:

touch or move it when hot

drop the bulb

scratch the bulb
Wear eye and hand protection.
Because of high voltage in Xenon lamps, it is
dangerous to replace the bulb or repair the
lamp and its components. We recommend
that you have such work done by a qualified
technician.!Do not replace the bulbs yourself. You could
otherwise damage the LEDs or parts of the
vehicle. Only have the LEDs replaced by an
authorized Mercedes-Benz Light Truck Center.

483 Practical hints
Replacing bulbs
Replacing bulbs for front lamps
Before you start to replace a bulb for a
front lamp, do the following first:
Turn the exterior lamp switch to
positionM (
page 143).
Open the hood (page 356).
Halogen headlamps
1Low beam/high beam headlamp cover2Bulb socket for turn signal lamp
2Bulb socket for turn signal lamp
3Bulb socket for low beam headlamp
4Bulb socket for high beam headlampLow beam headlamp bulbs
Turn cover 1 counterclockwise.
Remove cover 1.
Turn bulb socket 3 counterclockwise.
Pull bulb socket 3 out of the head-
lamp housing.
Pull the low beam bulb out of bulb
socket 3.
Insert the new low beam bulb into bulb
socket 3.
Insert bulb socket 3 into the head-
lamp housing.
Turn bulb socket 3 clockwise until it
engages.
Place cover 1 on the opening in the
headlamp housing.
Turn cover 1 clockwise until it
engages.

484 Practical hints
Replacing bulbs
High beam headlamp bulbs
Turn cover 1 counterclockwise.
Remove cover 1.
Turn bulb socket 4 counterclockwise.
Pull bulb socket 4 out of the head-
lamp housing.
Pull the high beam bulb out of bulb
socket 4.
Insert the new high beam bulb into bulb
socket 4.
Insert bulb socket 4 into the head-
lamp housing.
Turn bulb socket 4 clockwise until it
engages.
Place cover 1 on the opening in the
headlamp housing.
Turn cover 1 clockwise until it
engages.Front turn signal lamp bulbs
Pull bulb socket 2 out of the head-
lamp housing.
Pull the turn signal bulb out of bulb
socket 2.
Insert the new turn signal bulb into bulb
socket 2.
Insert bulb socket 2 into the head-
lamp housing.Bi-Xenon headlamps*
1Bulb socket for turn signal lamp
2Low beam/high beam headlamp cover
– Do not remove
1Bulb socket for turn signal lamp

485 Practical hints
Replacing bulbs
Low beam and high beam flasher spot
bulbs
Front turn signal lamp bulbs
Pull bulb socket 1 out of the head-
lamp housing.
Pull the turn signal bulb out of bulb
socket 1.
Insert the new turn signal bulb into bulb
socket 1.
Insert bulb socket 1 into the head-
lamp housing.Parking and standing lamp bulbs
1Bulb socket for parking and standing
lamp
Turn bulb socket 1 counterclockwise.
Pull bulb socket 1 out of the housing.
Pull the bulb out of bulb socket 1.
Insert the new parking and standing
lamp bulb into bulb socket 1.
Insert bulb socket 1 into the housing.
Turn bulb socket 1 clockwise until it
engages.Front fog lamp bulbs
1Front fog lamp
2Cover
3Retaining screws
Remove retaining screws3.
Take off cover 2.
Warning!G
Do not remove the low beam/high beam
cover for the Bi-Xenon* headlamp. Because
of high voltage in Bi-Xenon* lamps, it is dan-
gerous to replace the bulb or repair the lamp
and its components. We recommend that
you have such work done by a qualified
technician.
iThe following procedure also applies to
corner-illuminating front fog lamps*.


486 Practical hints
Replacing bulbs
4Screws
Remove screws4 that retain front fog
lamp 1.
Remove front fog lamp 1.5Front fog lamp bulb socket
Turn bulb socket 5 counterclockwise.
Pull bulb socket 5 out of the housing.
Pull the bulb out of bulb socket 5.
Insert the new front fog lamp bulb into
bulb socket 5.
Insert bulb socket 5 into the housing.
Turn bulb socket 5 clockwise until it
engages.
Insert front fog lamp 1 back into
bumper.
Fasten retaining screws4.
Reinsert cover 2 and press it in until it
engages.
Fasten retaining screws3.
iAn additional adapter cable is used to con-
nect the bulb socket with the vehicle’s electrical
circuit. Reuse the adapter cable after replacing
the bulb.


487 Practical hints
Replacing bulbs
Additional turn signal lamps bulbs
The additional turn signal lamps in the
exterior rear view mirrors have LEDs.
If a malfunction occurs or LEDs fail to
function, the entire turn signal unit must
be replaced. Have the turn signal unit re-
placed by an authorized Mercedes-Benz
Light Truck Center.
Front side marker lamp bulbs
Since replacing the side marker lamp bulbs
is a technically highly demanding process,
we recommend you have the side marker
lamp bulbs replaced by an authorized
Mercedes-Benz Light Truck Center.Replacing bulbs for rear lamps
Before you start to replace a bulb for a rear
lamp, do the following first:
Turn the combination switch to
positionM (
page 143).
Tail lamp unit
Open the tailgate (page 119).Opening the side trim panels
1Lock
2Cover in left side trim panel
1Lock
2Cover in right side trim panel
iTo access the tail lamp units, you have to
remove the cover in the corresponding side trim
panel of the cargo compartment.


488 Practical hints
Replacing bulbs
Insert a suitable object such as a coin
into the slot of lock1.
Turn lock1 clockwise (left side trim
panel) or counterclockwise (right side
trim panel) by 90° in direction of arrow.
Remove cover2.
Replacing bulbs
1Tail, side marker, standing, and parking
lamp bulb socket
2Turn signal lamp bulb socket
3Fog lamp bulb socket
(driver’s side only)
4Backup lamp bulb socket
Depending on which bulb needs to be
replaced, turn the respective bulb
socket 1 - 4 counterclockwise.
Pull the bulb socket out of the housing.
Similarly turn the bulb counterclock-
wise carefully and pull the bulb out of
bulb socket.
Insert the new bulb into the bulb
socket.
Turn the bulb in the bulb socket clock-
wise carefully.
Insert the bulb socket into the housing.
Turn the bulb socket clockwise until it
engages.License plate lamps
1License plate lamp cover
2Screw
Loosen screws2.
Remove license plate lamp cover1.
Replace the license plate lamp bulb.
Reinstall license plate lamp cover1.
Retighten screws2.


489 Practical hints
Replacing wiper blades
Replacing wiper blades
Front wiper blades
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status0
(
page 41).Removing
Fold the wiper arms forward until they
engage.
1Wiper blade
2Tab
3Wiper arm
Press tabs2 together.
Tilt wiper blade 1 away from wiper
arm 3.
Take off wiper blade 1 in direction of
arrow.
Warning!G
For safety reasons, switch off wipers and
remove SmartKey from starter switch
(vehicles with KEYLESS-GO*: Make sure
the vehicle’s on-board electronics have
status0) before replacing a wiper blade.
Otherwise the motor could suddenly turn on
and cause injury.
Warning!G
Wiper blades are components that are
subject to wear and tear. Replace the wiper
blades twice a year, preferably in the spring
and fall. Otherwise the windows will not be
properly wiped. As a result, you may not
be able to observe surrounding traffic condi-
tions and could cause an accident.
!Never open the hood when the wiper arms
are folded forward.
Hold on to the wiper when folding the wiper arm
back. If released, the force of the impact from
the tensioning spring could crack the windshield.
Do not allow the wiper arms to contact the wind-
shield glass without a wiper blade inserted.
For your convenience, we recommend that you
have this work carried out by an authorized
Mercedes-Benz Light Truck Center.!Do not pull on the wiper blade inserts. They
could tear.