2005 MERCEDES-BENZ SPRINTER Service Repair Manual

INSTALLATION
(1) Connect the wire harness connector to the
blower motor resistor block.
(2) Install the blower motor resistor into the ven-
tilation housing. The housing is indexed to allow
mounting in only one position.
(3) Reconnect the battery negative cable.
BLOWER MOTOR SWITCH
DESCRIPTION
The heater-A/C blower motor is controlled by a
thumbwheel-type blower motor switch, mounted in
the heater-A/C control. The switch allows the selec-
tion of four blower motor speeds with the ignition
switch in the On position.
NOTE: The blower motor will operate only at the
lowest speed when the Residual Engine Heat Utili-
zation (REST) function is selected, regardless of the
blower speed setting on the control panel.
OPERATION
When the ignition is turned to On, the integral
blower motor resistor within the ATC control module
supplies power to the blower motor switch. The
switch directs power to the individual blower driver
circuits through the blower motor resistor block to
the blower motor and then to ground.The blower motor switch cannot be repaired and, if
faulty or damaged, it must be replaced. The switch is
serviced only as a part of the heater-A/C control.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
The blower motor switch can be diagnosed by using
the DRBIIItscan tool. Refer to Body Diagnostic Pro-
cedures. For circuit descriptions and diagrams, refer
to the appropriate wiring information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The blower motor switch cannot be adjusted or
repaired, and if faulty or damaged, the heater-A/C
control must be replaced (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/A/C HEATER
CONTROL - REMOVAL).
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor is a two-wire
temperature sensing element located at the coldest
point on the face of the evaporator. The sensor is
attached to the evaporator coil fins. The evaporator
temperature sensor prevents condensation on the
evaporator coil from freezing and obstructing A/C
system air flow. The evaporator temperature sensor
cannot be adjusted or repaired and, if faulty or dam-
aged, it must be replaced.
Fig. 12 Blower Motor Resistor Block
1 - BLOWER MOTOR RESISTOR
2 - ELECTRICAL CONNECTOR
3 - VENTILATION HOUSING
VACONTROLS - FRONT 24 - 17
BLOWER MOTOR RESISTOR BLOCK (Continued)

OPERATION
The evaporator temperature sensor monitors the
temperature of the evaporator. The sensor will
change its internal resistance in response to the tem-
peratures it monitors. The ATC control module is
connected to the sensor through a sensor ground cir-
cuit and a sensor signal circuit. As the evaporator
temperature increases, the resistance of the sensor
decreases and the voltage monitored by the module
decreases. The module uses this monitored voltage
reading to an indication of the evaporator tempera-
ture. The ATC control module is programmed to
respond to this input by cycling the air conditioning
compressor clutch as necessary to optimize air condi-
tioning system performance and to protect the sys-
tem from evaporator freezing. The external location
of the sensor allows the sensor to be removed or
installed without disturbing the refrigerant in the
system. The evaporator temperature sensor is diag-
nosed by performing the ATC Function Test using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the radio (Refer to 8 - ELECTRICAL/
AUDIO/RADIO - REMOVAL).
(3) Remove glove compartment.
(4) Remove cover from instrument cluster (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - REMOVAL).
(5) Remove the instrument cluster (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - REMOV-
AL).
(6) Remove passenger side airbag.
(7) Remove cover above air nozzle on passenger
side.
(8) Remove speaker.
(9) Remove center section of instrument panel.
(10) Remove heater-A/C control from the instru-
ment panel (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS/A/C HEATER CONTROL -
REMOVAL).
(11) Remove instrument panel top section.
(12) Remove electrical connections.
(13) Remove air bezels from instrument panel.
(14) Disconnect the wire harness connector from
evaporator temperature sensor (Fig. 13).
(15) Remove evaporator temperature sensor from
heater housing.
INSTALLATION
(1) Install the new probe into the evaporator.
NOTE: The new probe must not go into the same
hole (in the evaporator core) that the old probe was
removed from.
(2) Install the wire harness connector to the evap-
orator temperature sensor.
(3) Install the air bezels to the instrument panel.
(4) Install the electrical connections.
(5) Install the instrument panel top section (Refer
to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - INSTALLATION).
(6) Install the heater-A/C control (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - INSTALLATION).
(7) Install the center section of the instrument
panel.
(8) Install the speaker (Refer to 8 - ELECTRICAL/
AUDIO/SPEAKER - INSTALLATION).
(9) Install the cover above the air nozzle on the
passenger side.
(10) Install the passenger side airbag.
(11) Install the instrument cluster (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - INSTAL-
LATION).
Fig. 13 Evaporator Temperature Sensor
1 - WIRE HARNESS CONNECTOR
2 - EVAPORATOR TEMPERATURE SENSOR
24 - 18 CONTROLS - FRONTVA
EVAPORATOR TEMPERATURE SENSOR (Continued)

(12) Install the cover to the instrument cluster.
(13) Install glove compartment.
(14) Install the radio (Refer to 8 - ELECTRICAL/
AUDIO/RADIO - INSTALLATION).
(15) Reconnect the battery negative cable.
IN-CAR TEMPERATURE
SENSOR
DESCRIPTION
The in-car temperature sensor measures the actual
air temperature within the passenger compartment.
The in-car temperature sensor is located inside of the
A/C-heater control behind a vented panel (Fig. 14)
and is not a separate serviceable component. The
A/C-heater control must be replaced if there is a fault
relating to the in-car temperature sensor.
OPERATION
Air from the passenger compartment flows over the
thermistor of the in-car temperature sensor. The
thermistor changes resistance with air temperature.
The ATC control module measures this resistance
and calculates the temperature of the air. The ATC
control module then makes adjustments to maintain
the selected passenger compartment temperature.
DIAGNOSIS AND TESTING
The in-car temperature sensor is diagnosed by per-
forming the ATC Function Test using the DRBIIIt
scan tool. Refer to Body Diagnostic Procedures. For
circuit descriptions and diagrams, refer to the appro-
priate wiring information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
If the in-car temperature sensor is verified to be
bad, the A/C-heater control must be replaced (Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS/A/C HEATER CONTROL - REMOVAL).
MODE DOOR CABLES
REMOVAL
The air distribution control cables (mode door
cables) can be removed and installed without having
to remove the instrument panel from the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center section of the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(3) Remove the heater-A/C control (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL).
(4) Mark and disconnect the control cables from
the A/C-heater control.
(5) Mark and disconnect the control cables from
the heater housing retainers (Fig. 15).
(6) Disconnect the control cables from the mode
door levers and remove the cables from the vehicle.
INSTALLATION
(1) Connect the two control cables to the mode
door levers (Fig. 16).
(2) Connect the two control cables to the A/C-
heater control.
NOTE: Install the control cable of bottom adjust-
ment lever to the front adjustment wheel of the A/C-
heater control.
(3) Hold the A/C-heater control in its installation
position.
Fig. 14 In-Car Temperature Sensor
1 - A/C-HEATER CONTROL
2 - IN-CAR TEMPERATURE SENSOR
VACONTROLS - FRONT 24 - 19
EVAPORATOR TEMPERATURE SENSOR (Continued)

NOTE: While holding the A/C-heater control in the
installation position, verify that the control cables
are not twisted.
(4) Turn the mode control knob on the A/C-heater
control to the nine-o-clock position.
(5) Turn the upper mode door lever counter-clock-
wise until it reaches its stop and install the cable
into the retainer in this position (arrow).
(6) Turn the lower mode door lever clockwise until
it reaches its stop and install the cable into the
retainer in this position (arrow).
(7) Operate the mode control knob and verify that
the mode door cables are properly adjusted.
(8) Install the A/C-heater control and the two
retaining screws. Tighten the screws to 2 N´m (17 in.
lbs.).
(9) Install the center section of the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(10) Reconnect the battery negative cable.
RECIRCULATION DOOR
ACTUATOR
DESCRIPTION
This vehicle uses a two-position vacuum operated
recirculation door actuator to move the recirculation
door. Vacuum supply to the recirculation door actua-
tor is controlled by an integral electronic control sole-
noid. The recirculation door actuator is mounted on
the outboard side of the ventilation housing above
the blower motor in the engine compartment.
OPERATION
The recirculation door actuator uses engine vac-
uum, which is controlled by an integral electrical
solenoid. The electrical solenoid is connected to the
ATC control through the vehicle electrical system by
a dedicated two-wire lead and connector. The output
shaft of the recirculation door actuator is keyed to a
pivot shaft, which is keyed to the recirculation door
shaft. The recirculation door actuator can move the
recirculation door in two directions.
The recirculation door actuator is controlled by an
electrical switch that is integral to the heater-A/C
control. When the rotary-type mode control knob is
moved to the recirculation position, a signal is sent to
the electrical solenoid within the recirculation door
actuator. This signal causes the solenoid to open a
port to engine vacuum which pulls the output shaft
into the actuator, which moves the recirculation door.
Fig. 15 Air Distribution Control Cables
1 - AIR DISTRIBUTION CONTROL CABLES
2 - ADJUSTMENT LEVERS
3 - HEATER HOUSING
Fig. 16 Adjusting Air Distribution Control Cables
1 - MODE CONTROL KNOB
2 - UPPER MODE DOOR CABLE
3 - UPPER MODE DOOR LEVER
4 - LOWER MODE DOOR LEVER
5 - LOWER MODE DOOR CABLE
6 - HEATER-A/C CONTROL
24 - 20 CONTROLS - FRONTVA
MODE DOOR CABLES (Continued)

The actuator is spring loaded so the door moves to
the outside-air position when no vacuum is supplied
through the electrical solenoid.
The recirculation door actuator can be diagnosed
by performing the ATC Function Test using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures. The recirculation door actuator cannot be
repaired and, if faulty or damaged, it must be
replaced.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connector from the
recirculation door actuator (Fig. 17).
(3) Disconnect the vacuum line from the recircula-
tion door actuator.
(4) Remove the two screws that secure the recircu-
lation door actuator to the ventilation housing.
(5) Disconnect the actuator shaft from the recircu-
lation door pivot lever and remove the actuator from
the vehicle.
INSTALLATION
(1) Connect the actuator shaft to the recirculation
door pivot lever.
(2) Install the two screws that secure the recircu-
lation door actuator to the ventilation housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Connect the vacuum line to the recirculation
door actuator.
(4) Connect the wire harness connector to the
recirculation door actuator.
(5) Reconnect the battery negative cable.
Fig. 17 Recirculation Door Actuator
1 - WIRE HARNESS CONNECTOR
2 - RECIRCULATION DOOR ACTUATOR
3 - SCREW (2)
4 - PIVOT LEVER
5 - ACTUATOR SHAFT
6 - VACUUM LINE
VACONTROLS - FRONT 24 - 21
RECIRCULATION DOOR ACTUATOR (Continued)

CONTROLS - REAR
TABLE OF CONTENTS
page page
BLOWER MOTOR SWITCH
DESCRIPTION.........................22
OPERATION...........................22
DIAGNOSIS AND TESTING................23
REMOVAL.............................23
INSTALLATION.........................23
BLOWER MOTOR RELAY
DESCRIPTION.........................23
OPERATION...........................23
DIAGNOSIS AND TESTING................24
REMOVAL.............................24
INSTALLATION.........................24
CONTROL MODULE
DESCRIPTION.........................24
OPERATION...........................24
DIAGNOSIS AND TESTING................24
REMOVAL.............................24
INSTALLATION.........................25
EVAPORATOR TEMPERATURE SENSOR
DESCRIPTION.........................25
OPERATION...........................26DIAGNOSIS AND TESTING................26
REMOVAL.............................26
INSTALLATION.........................26
SOLENOID VALVE
DESCRIPTION.........................27
OPERATION...........................27
DIAGNOSIS AND TESTING................27
REMOVAL.............................27
INSTALLATION.........................28
TEMPERATURE CONTROL
DESCRIPTION.........................29
OPERATION...........................29
DIAGNOSIS AND TESTING................29
REMOVAL.............................29
INSTALLATION.........................29
TEMPERATURE SENSOR
DESCRIPTION.........................30
OPERATION...........................30
DIAGNOSIS AND TESTING................30
REMOVAL.............................30
INSTALLATION.........................30
BLOWER MOTOR SWITCH
DESCRIPTION
The optional rear A/C unit blower motor is con-
trolled by a three position rocker switch (Fig. 1),
mounted in the switch panel on the instrument
panel. The switch allows the selection of one of two
blower motor speeds and an Off position only when
the A/C switch on the front A/C-heater control is acti-
vated.
OPERATION
With the front A/C switch activated, the rear
blower motor speed can be selected by pressing the
rocker switch upwards (high speed) or downwards
(low speed). To turn the rear blower motor off, switch
the blower motor switch to the center position.
Depending on the blower motor switch position, a
blower motor speed command signal is sent to one of
the two blower motor relays. When activated, relay 1
sends power through an integral resistor within the
rear A/C control module and then to the blower
motor, while relay 2 when activated, sends power
directly to the blower motor.
The rear blower motor switch cannot be repaired
and, if faulty or damaged, it must be replaced.
Fig. 1 Rear Air Conditioning Switch
24 - 22 CONTROLS - REARVA

DIAGNOSIS AND TESTING
Before testing the rear blower motor switch, verify
that the front A/C system is functional by performing
the ATC Fuction Test using the DRBIIItscan tool.
Use a volt/ohmmeter to test the rear blower motor
switch. For circuit descriptions and diagrams, refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
ness routing and retention, connector pin-out infor-
mation and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the
rear blower motor switch.
(3) Check for continuity between terminal 10 and
terminals 1, 7 and 4 of the blower motor switch. In
all instances, there should be continuity.
NOTE: To check the switch's internal circuits, con-
nect the negative lead of the ohmmeter to terminal
10 and the positive ohmmeter lead to terminals 1, 7
and 4. To check the switch's integral light emitting
diodes, reverse the ohmmeter leads.
(4) Check for continuity between the rear blower
motor switch terminals 3 and 7 as you move the
blower motor switch to each of the two speed posi-
tions, and the Off position. There should be continu-
ity in only one blower motor switch speed position.
(5) Check for continuity between the rear blower
motor switch terminals 4 and 8 as you move the
blower motor switch to each of the two speed posi-
tions, and the Off position. There should be continu-
ity in only the other blower motor switch speed
position.
(6) If OK, test and repair the rear blower motor
switch wire harness circuits. If not OK, replace the
faulty rear blower motor switch.
REMOVAL
NOTE: The rear blower motor switch is used only
on models with the optional rear A/C unit.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the blower motor switch from the
switch panel.
(3) Disconnect the wire harness connector from the
rear blower motor switch and remove the switch from
the vehicle.
INSTALLATION
(1) Connect the wire harness connector to the rear
blower motor switch.
(2) Install the blower motor switch into the switch
panel.
(3) Reconnect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relays are an International Stan-
dards Organization (ISO)-type relay. The relays are
electro-mechanical devices which when energized,
directs fused battery current to the rear blower
motor. The relay coils are energized when they
receives a voltage signal from the blower motor
switch.
OPERATION
When the rear blower motor switch is in the low
speed position, the switch directs a voltage signal to
the high side of rear blower relay #1 and energizes
its relay coil. When energized, the low side of blower
relay #1 directs fused battery current through an
integral blower resistor to the rear blower motor.
When in the high speed position, the rear blower
switch directs a voltage signal to the high side of
rear blower relay #2 and energizes its relay coil.
When energized, the low side of blower relay #2
directs fused battery current through an integral
blower resistor to the rear blower motor.
The rear blower motor relays are located in the
relay block of the rear evaporator housing. Refer to
the appropriate wiring diagrams for more informa-
tion.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
VACONTROLS - REAR 24 - 23
BLOWER MOTOR SWITCH (Continued)

DIAGNOSIS AND TESTING
The #1 and #2 rear blower motor relays (Fig. 2) are
located in the relay block of the rear evaporator
housing. Remove the rear blower motor relays from
the relay block to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, refer to the appropriate wiring infor-
mation for circuit descriptions and diagrams. If not
OK, replace the faulty relay.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the rear evaporator
housing.
(3) Refer to the relay block for blower motor relay
identification.
(4) Unplug the blower motor relay from the relay
block and remove it.
INSTALLATION
(1) Install the blower motor relay by aligning the
relay terminals with the cavities in the relay block
and pushing the relay firmly into place.
(2) Install the rear evaporator cover.(3) Reconnect the battery negative cable.
CONTROL MODULE
DESCRIPTION
The rear A/C control module is mounted to the
upper left side of the rear evaporator housing in the
rear compartment, where it can be accessed for ser-
vice.
The rear A/C control module has wire connections
to the rear A/C blower motor switch, rear evaporative
temperature sensor, solenoid valve, rear A/C temper-
ature control and the temperature sensor. The rear
A/C control module cannot be repaired and, if faulty
or damaged, it must be replaced.
OPERATION
The rear A/C control module is supplied battery
power through the rear blower switch and a 7.5 amp
fuse. The control module receives input signals from
the rear A/C blower motor switch, rear A/C tempera-
ture control, rear temperature sensor and the rear
evaporator temperature sensor when the front A/C
switch is turned on. The rear A/C control module
uses the input signals to control rear blower motor
speed and output air temperature, and to prevent
freezing of the rear evaporator core.
DIAGNOSIS AND TESTING
For circuit descriptions and diagrams, refer to Air
Conditioning/Heater in Group 8W - Wiring Diagrams.
NOTE: Prior to checking rear A/C control module
circuits, verify that the front A/C system is operat-
ing properly.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the rear dome light from the rear roof
duct panel (Fig. 3).
(3) Disconnect the dome light wire harness connec-
tor and remove the dome light from vehicle.
(4) Remove the six push-pin roof duct panel fasten-
ers and remove the duct panel from the vehicle.
(5) Remove the five evaporator panel screws at the
front of the panel.
(6) If equipped, remove the interior motion sensor
from the evaporator panel, disconnect the wire har-
ness connector and remove the motion sensor from
the vehicle (Fig. 4).
(7) Remove the three push-in evaporator panel fas-
teners at the rear of the panel.
Fig. 2 Blower Motor Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
24 - 24 CONTROLS - REARVA
BLOWER MOTOR RELAY (Continued)