2005 MERCEDES-BENZ SPRINTER air condition

(6) Disconnect the two wiring harness connectors
from the A/C-heater control.
(7) If A/C-heater control is to be replaced, remove
the two mounting brackets from the A/C-heater con-
trol.
INSTALLATION
(1) If removed, install the two mounting brackets
to the A/C-heater control.
(2) Connect the two wire harness connectors into
the back of the A/C-heater control.
(3) 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 theA/C-
heater control.
(4) Position the A/C-heater control into the instru-
ment panel.
(5) Install the two A/C-heater control retaining
screws. Tighten the screws to 2 N´m (17 in. lbs.).
(6) Install the center bezel onto the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(7) Reconnect the battery negative cable.
A/C PRESSURE TRANSDUCER
DESCRIPTION
The A/C pressure transducer is installed on the liq-
uid line fitting located at the top of the receiver/drier.
A rubber O-ring seals the connection between the
transducer and the fitting. Three terminals within a
molded plastic connector receptacle on the top of the
transducer connect it to the vehicle electrical system
through a wire lead and connector.
The A/C pressure transducer cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The A/C pressure transducer monitors the pres-
sures in the high side of the refrigerant system
through its connection to a fitting on the liquid line.
The transducer will change its internal resistance in
response to the pressures it monitors. The ATC con-
trol module provides a five volt reference signal and
monitors the output voltage of the transducer on the
transducer return circuit to determine refrigerant
pressure. The ATC module is preprogrammed to
respond to this and other sensor inputs by controlling
the operation of the air conditioning compressor
clutch and the auxiliary radiator cooling fan to help
optimize air conditioning system performance and to
protect the system components from damage. The
A/C pressure transducer input to the ATC module
also prevents the A/C compressor clutch from engag-
ing when the ambient temperature is below 0.556É C
(33É F) due to the pressure/temperature relationship
of the refrigerant. The A/C pressure transducer is
diagnosed by performing the ATC Function Test
using the DRBIIItscan tool. Refer to Body Diagnos-
tic Procedures.
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER
The A/C pressure transducer is tested using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures. Before testing the A/C pressure transducer, be
certain that the transducer wire harness connections
are clean of corrosion and properly connected. For
the air conditioning system to operate, an A/C pres-
sure transducer voltage reading between 0.7 and 4.56
volts is required. Voltage outside this range indicate
a low or high refrigerant system pressure condition
to the ATC control module. The control module is
programmed to respond to a low or high refrigerant
system pressure by suppressing operation of the com-
pressor. Refer to the A/C Pressure Transducer Volt-
age chart for the possible condition indicated by the
transducer voltage readings.
Fig. 8 A/C-Heater Control
1 - A/C-HEATER CONTROL
2 - CONTROL CABLE
3 - CONTROL CABLE
4 - WIRE HARNESS CONNECTOR
5 - WIRE HARNESS CONNECTOR
6 - MOUNTING BRACKET (2)
7 - SCREW (2)
VACONTROLS - FRONT 24 - 13
A/C HEATER CONTROL (Continued)

A/C PRESSURE TRANSDUCER VOLTAGE
Voltage Possible Cause
0.0 1. No transducer supply voltage from ATC control module.
2. Shorted transducer circuit.
3. Faulty transducer.
0.150 to 0.450 1. Ambient temperature below 10É C (50É F).
2. Low refrigerant system pressure.
0.451 to 4.519 1. Normal refrigerant system pressure.
4.520 to 4.850 1. High refrigerant system pressure.
5.0 1. Open transducer circuit.
2. Faulty transducer.
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE).
(2) Disconnect and isolate the battery negative
cable.
(3) Disconnect the wire harness connector from the
A/C pressure transducer (Fig. 9).
(4) Using an open end wrench, remove the A/C
pressure transducer from the fitting on the liquid
line.
(5) Remove the O-ring seal from the A/C pressure
transducer and discard.
INSTALLATION
(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the A/C pressure trans-
ducer.
(2) Using an open end wrench, install and tighten
the A/C pressure transducer into the fitting on the
liquid line. Tighten the transducer to 12 N´m (106 in.
lbs.).
(3) Reconnect the wire harness connector to the
transducer.
(4) Reconnect the battery negative cable.
(5) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(6) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
AIR OUTLET TEMPERATURE
SENSOR
DESCRIPTION
The air outlet temperature sensor is a two-wire
temperature sensing element that detects the tem-
perature of the air coming out of the heater housing
unit. The sensor is attached to heater housing unit
directly behind the ATC heater-A/C control panel.
The thermistor will change resistance as the temper-
ature changes.
The air outlet temperature sensor cannot be
adjusted or repaired, and if faulty or damaged, it
must be replaced.
Fig. 9 A/C Pressure Transducer
1 - WIRE HARNESS CONNECTOR
2 - A/C PRESSURE TRANSDUCER
3 - O-RING SEAL
4 - LIQUID LINE FITTING
24 - 14 CONTROLS - FRONTVA
A/C PRESSURE TRANSDUCER (Continued)

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)

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
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)

(8) Remove the rear evaporator panel from the
vehicle.
(9) Disconnect the wire harness connectors from
the rear A/C control module (Fig. 5).
(10) Remove the rear A/C control module retainers
and the control module from the vehicle.
INSTALLATION
(1) Install the rear A/C control module and control
module retainers.
(2) Connect the wire harness connectors to the
rear A/C control module.
(3) Install the rear evaporator panel onto the rear
evaporator housing and install the three push-pin
fasteners.
(4) If equipped, connect the wire harness connector
to the interior motion sensor and install the sensor
into the evaporator panel.
(5) Install the five evaporator panel screws at the
front of the panel. Tighten the screws to 2 N´m (17
in. lbs.).
(6) Install the roof duct panel and the six push-pin
fasteners.
(7) Connect the dome light wire harness connector
and install the dome light into the roof duct panel.
(8) Reconnect the battery negative cable.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The rear evaporator temperature sensor is used to
signal the rear A/C control module to cycle the rear
A/C solenoid valve open and closed in order to control
rear evaporator temperature. Controlling the evapo-
rator temperature prevents condensation on the
evaporator fins from freezing and obstructing rear air
conditioning system air flow.
Fig. 3 Rear Roof Duct Panel
1 - SCREW (5)
2 - PUSH-PIN FASTENER (6)
3 - REAR DOME LAMP
4 - ROOF DUCT PANEL
Fig. 4 Rear Evaporator Panel
1 - REAR EVAPORATOR PANEL
2 - PUSH-PIN FASTENER (3)
3 - INTERIOR MOTION SENSOR
Fig. 5 Rear A/C Control Module
1 - REAR A/C CONTROL MODULE
2 - REAR EVAPORATOR BLOWER MOTOR
VACONTROLS - REAR 24 - 25
CONTROL MODULE (Continued)