fuse diagram MERCEDES-BENZ SPRINTER 2006 Owner's Manual

INTERMITTENT AND POOR CONNECTIONS
Most intermittent electrical problems are caused
by faulty electrical connections or wiring. It is also
possible for a sticking component or relay to cause a
problem. Before condemning a component or wiring
assembly, check the following items.
²Connectors are fully seated
²Spread terminals, or terminal push out
²Terminals in the wiring assembly are fully
seated into the connector/component and locked into
position
²Dirt or corrosion on the terminals. Any amount
of corrosion or dirt could cause an intermittent prob-
lem
²Damaged connector/component casing exposing
the item to dirt or moisture
²Wire insulation that has rubbed through causing
a short to ground
²Some or all of the wiring strands broken inside
of the insulation
²Wiring broken inside of the insulation
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are
six steps which can aid in the procedure. The steps
are listed and explained below. Always check for non-
factory items added to the vehicle before doing any
diagnosis. If the vehicle is equipped with these items,
disconnect them to verify these add-on items are not
the cause of the problem.
(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are
in the same circuit. Refer to the wiring diagrams.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem area.(6) Verify the proper operation. For this step,
check for proper operation of all items on the
repaired circuit. Refer to the wiring diagrams.
STANDARD PROCEDURE
ELECTROSTATIC DISCHARGE (ESD) SENSITIVE
DEVICES
All ESD sensitive components are solid state and a
symbol (Fig. 5) is used to indicate this. When han-
dling any component with this symbol, comply with
the following procedures to reduce the possibility of
electrostatic charge build up on the body and inad-
vertent discharge into the component. If it is not
known whether the part is ESD sensitive, assume
that it is.
(1) Always touch a known good ground before han-
dling the part. This should be repeated while han-
dling the part and more frequently after sliding
across a seat, sitting down from a standing position,
or walking a distance.
(2) Avoid touching electrical terminals of the part,
unless instructed to do so by a written procedure.
(3) When using a voltmeter, be sure to connect the
ground lead first.
(4) Do not remove the part form it's protective
packing until it is time to install the part.
(5) Before removing the part from it's pakage,
ground the pakage to a known good ground on the
vehicle.
TESTING FOR VOLTAGE POTENTIAL
(1) Connect the ground lead of a voltmeter to a
known good ground (Fig. 6).
(2) Connect the other lead of the voltmeter to the
selected test point. The vehicle ignition may need to
be turned ON to check voltage. Refer to the appropri-
ate test procedure.
TESTING FOR CONTINUITY
(1) Remove the fuse for the circuit being checked
or, disconnect the battery.
(2) Connect one lead of the ohmmeter to one side
of the circuit being tested (Fig. 7).
Fig. 4 Probing Tool
1 - SPECIAL TOOL 6801
2 - PROBING END
Fig. 5 ELECTROSTATIC DISCHARGE SYMBOL
VA8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 7

(3) Connect the other lead to the other end of the
circuit being tested. Low or no resistance means good
continuity.
TESTING FOR A SHORT TO GROUND
(1) Remove the fuse and disconnect all items
involved with the fuse.
(2) Connect a test light or a voltmeter across the
terminals of the fuse.(3) Starting at the fuse block, wiggle the wiring
harness about six to eight inches apart and watch
the voltmeter/test lamp.
(4) If the voltmeter registers voltage or the test
lamp glows, there is a short to ground in that gen-
eral area of the wiring harness.
TESTING COMPONENTS FOR A SHORT TO
GROUND ON A FUSE POWERING SEVERAL
LOADS
(1) Refer to the wiring diagrams and disconnect or
isolate all items on the suspected fused circuit.
(2) Replace the blown fuse.
(3) Supply power to the fuse by turning ON the
ignition switch or re-connecting the battery.
(4) Start connecting the items in the fused circuit
one at a time. When the fuse blows the component
with the short to ground has been isolated.
TESTING FOR A VOLTAGE DROP
(1) Connect the positive lead of the voltmeter to
the side of the circuit closest to the battery (Fig. 8).
(2) Connect the other lead of the voltmeter to the
other side of the switch, component or circuit.
(3) Operate the item.
(4) The voltmeter will show the difference in volt-
age between the two points.Fig. 6 Testing for Voltage Potential
Fig. 7 Testing for Continuity
1 - FUSE REMOVED FROM CIRCUITFig. 8 Testing for Voltage Drop
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8W-97 POWER DISTRIBUTION
TABLE OF CONTENTS
page page
POWER DISTRIBUTION
DESCRIPTION..........................1
OPERATION............................1
CIGAR LIGHTER OUTLET
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET.............................2
REMOVAL.............................2
CIRCUIT BREAKER
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING - CIRCUIT
BREAKER............................2
FUSE BLOCK #1
DESCRIPTION..........................2
OPERATION............................3
REMOVAL.............................3
INSTALLATION..........................3FUSE BLOCK #2
DESCRIPTION..........................3
OPERATION............................3
POWER DISTRIBUTION CENTER
DESCRIPTION..........................3
OPERATION............................3
POWER OUTLET
DESCRIPTION..........................3
OPERATION............................4
DIAGNOSIS AND TESTING - POWER OUTLET . 4
REMOVAL.............................4
INSTALLATION..........................4
RELAY
DESCRIPTION..........................4
OPERATION............................5
DIAGNOSIS AND TESTING - RELAY.........5
REMOVAL.............................5
INSTALLATION..........................5
POWER DISTRIBUTION
DESCRIPTION
This section describes the power distribution com-
ponents used on this model as well as the methods in
which battery voltage and charging system voltage is
distributed throughout the vehicle. The power distri-
bution system for this vehicle consists of the follow-
ing major components which are covered in further
detail later in this section:
²Fuseblock #1
²Fuseblock #2
²Power Distribution Center (PDC)
The power distribution system also incorporates
various types of circuit control and protection fea-
tures, including:
²Automatic resetting circuit breakers
²Blade-type fuses
²Cartridge fuses
²Relays
Following are general descriptions and theory of
operation for the major components in the power dis-
tribution system. Refer to Wiring for the location of
complete circuit diagrams for the various power dis-
tribution system components.
OPERATION
The power distribution system for this vehicle is
designed to provide safe, reliable, and centralized dis-
tribution points for the electrical current required to
operate all of the standard and optional factory-in-
stalled electrical and powertrain, chassis, safety,
security and convenience systems. At the same time,
the power distribution system was designed to pro-
vide easy access to these electrical distribution points
for the vehicle technician to use when conducting
diagnosis and repair of faulty circuits. The power dis-
tribution system can also prove useful for the addi-
tion of electrical circuits that may be required to
operate accessories that the vehicle owner may
choose to have installed in the aftermarket.
CIGAR LIGHTER OUTLET
DESCRIPTION
The cigar lighter outlet is installed in the instru-
ment panel, near the center of the instrument panel.
The cigar lighter outlet is secured by a snap fit
within the instrument panel.
The cigar lighter knob/heating element, and the
cigar lighter outlet are available for service. These
components cannot be repaired and, if faulty or dam-
aged, they must be replaced.
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OPERATION
The cigar lighter consists of two major components:
a knob and heating element unit, and the cigar
lighter base or receptacle shell. The receptacle shell
is connected to ground, and an insulated contact in
the bottom of the shell is connected to battery cur-
rent. The cigar lighter receives battery voltage from a
fuse in the fuseblock only when the ignition switch is
in the Accessory or On positions.
The knob and heating element are encased within
a spring-loaded housing, which also features a sliding
protective heat shield. When the heating element is
inserted in the receptacle shell, the heating element
resistor coil is grounded through its housing to the
receptacle shell. If the cigar lighter knob is pushed
inward, the heat shield slides up toward the knob
exposing the heating element.
Two small spring-clip retainers are located on
either side of the insulated contact inside the bottom
of the receptacle shell. These clips engage and hold
the heating element against the insulated contact
long enough for the resistor coil to heat up and glow.
When the resistor coil becomes sufficiently heated,
excess heat radiates from the heating element caus-
ing the spring-clips to expand. Once the spring-clips
expand far enough to release the heating element,
the spring-loaded housing forces the knob and heat-
ing element to pop back outward to their relaxed
position. When the cigar lighter knob and element
are pulled out of the receptacle shell, the protective
heat shield slides downward on the housing so that
the heating element is recessed and shielded around
its circumference for safety.
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET
For cigar lighter outlet diagnosis and testing pro-
cedures (Refer to 8 - ELECTRICAL/POWER DISTRI-
BUTION/POWER OUTLET - DIAGNOSIS AND
TESTING)
REMOVAL
For cigar lighter outlet removal procedure (Refer to
8 - ELECTRICAL/POWER DISTRIBUTION/POWER
OUTLET - REMOVAL).
CIRCUIT BREAKER
DESCRIPTION
Automatic resetting circuit breakers are used to
protect the power window voltage supply circuits.
These circuit breakers can protect the systems from a
short circuit, or from an overload condition caused byan obstructed or stuck power window regulator or
switch.
The circuit breaker cannot be repaired and, if
faulty or damaged, it must be replaced.
OPERATION
The circuit breaker contains a bi-metal strip sand-
wiched between two contacts forming the connection
in the circuit. An overload condition causes the
bi-metal strip to heat and bend to the open position,
disconnecting current flow to the circuit. Then as the
system overload or short circuit is removed, the
bi-metal strip cools, re-establishing contact to allow
current flow to the circuit.
DIAGNOSIS AND TESTING - CIRCUIT BREAKER
For complete circuit descriptions and diagrams,
refer toWiring.
(1) Locate the correct circuit breaker in the fuse-
block. Pull out the circuit breaker slightly, but be cer-
tain that the circuit breaker terminals still contact
the terminals in the fuseblock cavities.
(2) Connect the negative lead of a 12-volt DC volt-
meter to a good ground.
(3) With the voltmeter positive lead, check both
terminals of the circuit breaker for battery voltage.
If only one terminal has battery voltage, the circuit
breaker is faulty and must be replaced. If neither ter-
minal has battery voltage, repair the open circuit
from the Power Distribution Center as required.
FUSE BLOCK #1
DESCRIPTION
An electrical fuse block is concealed under the
driver side steering column. The fuse block serves to
distribute electrical current to many of the electrical
systems in the vehicle. The fuse block contains blade-
type mini fuses, relays and micro processors that
enable automatic control of some of the power distri-
bution circuits throughout the vehicle.
The molded plastic fuse block housing has an inte-
gral mounting bracket that is secured with screws to
the steering column. A finger recess is molded into
the cover for easy removal. A fuse layout map is
molded onto the back side of the cover to ensure
proper fuse identification.
The fuse block cannot be repaired, if the fuse block
is faulty or damaged or if any internal circuit is
faulty or damaged, the entire fuse block must be
replaced.
8W - 97 - 2 8W-97 POWER DISTRIBUTIONVA

OPERATION
All of the circuits entering and leaving the fuse
block do so through the instrument panel wire har-
ness. Internal connection of all of the fuse block cir-
cuits is accomplished by an intricate combination of
hard wiring and bus bars. Internal relays and micro
processors allow the vehicle electronics to control
some of the power distribution circuits throughout
the vehicle. Refer to the Wiring section for complete
circuit diagrams.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove fuse block cover by rotating locking
screw 90É.
(3) Remove the steering column cover. Refer to the
Body section for the procedure.
(4) Unscrew fuse block connections and disconnect
all electrical connectors from the fuse block.
(5) Remove the fuse block from the steering col-
umn.
INSTALLATION
(1) Position the fuse block in the steering column.
(2) Install fuse block connections and connect all
electrical connectors on the fuse block.
(3) Install the steering column cover. Refer to the
Body section for the procedure.
(4) Install fuse block cover by rotating locking
screw 90É.
(5) Connect the negative battery cable.
(6) Set time and radio stations.
FUSE BLOCK #2
DESCRIPTION
An electrical fuse block is concealed under the
driver side front seat. The fuse block serves to dis-
tribute electrical current to many of the electrical
systems in the vehicle. The fuse block houses blade-
type mini fuses, blade-type automatic resetting cir-
cuit breakers and International Standards
Organization relays. Additional provisions are avail-
able in the fuse block for additional fuses and ISO
relays.
The molded plastic fuse block housing has an inte-
gral mounting bracket that is secured with screws to
the seat base. The driver side seat base also has a
snap-fit fuse access panel that can be removed for
service of the fuses and the relays. A finger recess is
molded into one end for easy removal. A fuse layout
map is molded onto the back side of the panel to
ensure proper fuse identification.
The fuse block is integral to the body wire harness.
If any internal circuit or the fuse block housing isfaulty or damaged, the entire fuse block and body
wire harness unit must be replaced.
OPERATION
All of the circuits entering and leaving the fuse
block do so through the body wire harness. Internal
connection of all of the fuse block circuits is accom-
plished by an intricate combination of hard wiring
and bus bars.
POWER DISTRIBUTION CEN-
TER
DESCRIPTION
All of the electrical current distributed throughout
this vehicle is directed through the Power Distribu-
tion Center (PDC). The molded plastic PDC housing
is located in the left front corner of the engine com-
partment, on the battery positive cable. The PDC
housing has a molded plastic cover that slides over
the PDC housing. The PDC cover is easily opened or
removed for service access.
The PDC unit cannot be repaired and is only ser-
viced as a unit with the headlamp and dash wire
harness. If the internal circuits or the PDC housing
are faulty or damaged, the headlamp and dash wire
harness unit must be replaced.
OPERATION
All of the current from the battery and the gener-
ator output enters the PDC through the positive bat-
tery cable. The PDC cover is removed to access the
battery and generator output connection B(+) termi-
nal studs. Internal connection of all of the PDC cir-
cuits is accomplished by an intricate combination of
hard wiring and bus bars. Refer to Wiring Diagrams
for the location of complete PDC circuit diagrams.
POWER OUTLET
DESCRIPTION
The power outlet is installed in the instrument
panel accessory switch plate, which is located near
the center of the instrument panel. The power outlet
base is secured by a snap fit within the instrument
panel. A plastic protective cap snaps over the power
outlet base when the power outlet is not being used.
While the power outlet is very similar to a cigar
lighter base unit, it does not include the two small
spring-clip retainers inside the bottom of the recepta-
cle shell that are used to secure the cigar lighter
heating element to the insulated contact.
The power outlet receptacle unit are available for
service. The power outlet receptacle cannot be
VA8W-97 POWER DISTRIBUTION 8W - 97 - 3