2006 MERCEDES-BENZ SPRINTER charging

TERMINOLOGY
This is a list of terms and definitions used in the
wiring diagrams.
LHD.................Left Hand Drive Vehicles
RHD ...............Right Hand Drive Vehicles
ATX . . Automatic Transmissions-Front Wheel Drive
MTX . . . Manual Transmissions-Front Wheel Drive
AT....Automatic Transmissions-Rear Wheel Drive
MT .....Manual Transmissions-Rear Wheel Drive
SOHC...........Single Over Head Cam Engine
DOHC..........Double Over Head Cam Engine
Built-Up-Export....... Vehicles Built For Sale In
Markets Other Than North America
Except Built-Up-Export . Vehicles Built For Sale In
North America
CIRCUIT INFORMATION
Each wire shown in the diagrams contains a code
which identifies gage of wire, and color.
WIRE COLOR CODE CHART
COLOR CODE COLOR
BL BLUE
BK BLACK
BR BROWN
DB DARK BLUE
DG DARK GREEN
GY GRAY
LB LIGHT BLUE
LG LIGHT GREEN
OR ORANGE
PK PINK
RD RED
TN TAN
VT VIOLET
WT WHITE
YL YELLOW
* WITH TRACER
SECTION IDENTIFICATION AND INFORMATION
The wiring diagrams are grouped into individual
sections. If a component is most likely found in a par-
ticular group, it will be shown complete (all wires,
connectors, and pins) within that group. For exam-
ple, the Auto Shutdown Relay is most likely to be
found in Group 30, so it is shown there complete. It
can, however, be shown partially in another group if
it contains some associated wiring.
Splice diagrams in Section 8W-70 show the entire
splice and provide references to other sections thesplices serves. Section 8W-70 only contains splice dia-
grams that are not shown in their entirety some-
where else in the wiring diagrams.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the name/number on the dia-
gram pages.
WIRING SECTION CHART
GROUP TOPIC
8W-01 thru 8W-
09General information and Diagram
Overview
8W-10 thru 8W-
19Main Sources of Power and Ve-
hicle Grounding
8W-20 thru 8W-
29Starting and Charging
8W-30 thru 8W-
39Powertrain/Drivetrain Systems
8W-40 thru 8W-
49Body Electrical items and A/C
8W-50 thru 8W-
59Exterior Lighting, Wipers and
Trailer Tow
8W-60 thru 8W-
69Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-91 Connector, Ground and Splice
Locations
CONNECTOR, GROUND, AND SPLICE INFOR-
MATION
CAUTION: Not all connectors are serviced. Some
connectors are serviced only with a harness. A typ-
ical example might be the Supplemental Restraint
System connectors. Always check parts availability
before attempting a repair.
IDENTIFICATION
In-line connectors are identified by a number, as
follows:
²In-line connectors located in the engine compart-
ment are C100 series numbers
²In-line connectors located in the Instrument
Panel area are C200 series numbers.
²In-line connectors located in the body are C300
series numbers.
²Jumper harness connectors are C400 series
numbers.
VA8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 5

8W-20 CHARGING SYSTEM
Component Page
Battery.................... 8W-20-2, 3, 4, 5, 6
Battery Relay-Auxiliary............. 8W-20-2, 3
Battery-Auxiliary.................... 8W-20-3
D+ Relay No. 1...................... 8W-20-3
Engine Control Module................ 8W-20-6
Fuel Pump Relay.................... 8W-20-6
Fuse 1............................ 8W-20-2
Fuse 2.......................... 8W-20-2, 4
Fuse 3.......................... 8W-20-2, 5
Fuse 4.......................... 8W-20-2, 5
Fuse 5.......................... 8W-20-2, 5
Fuse 6.......................... 8W-20-2, 5
Fuse 7............................ 8W-20-4
Fuse 9............................ 8W-20-3
Fuse 19............................ 8W-20-3Component Page
Fuse Block No. 1................ 8W-20-4, 5, 6
Fuse Block No. 2.................... 8W-20-3
Fuse Block No. 3.................... 8W-20-3
G200.............................. 8W-20-2
G202............................ 8W-20-3, 4
Generator.......................... 8W-20-2
Glow Plug Control Module............. 8W-20-5
Ignition Switch...................... 8W-20-5
Instrument Cluster................... 8W-20-2
Optional Equipment Relay............. 8W-20-4
Power Distribution Center......... 8W-20-2, 4, 5
Relay Block........................ 8W-20-4
Starter Motor..................... 8W-20-2, 6
Starter Motor Relay.................. 8W-20-6
VA8W-20 CHARGING SYSTEM 8W - 20 - 1

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.
VA8W-97 POWER DISTRIBUTION 8W - 97 - 1

INSTALLATION
CAUTION: Care must be taken to closley inspect
the gasket area around the time case cover to cyl-
inder head gasket coolant port. If damage is found,
replace the cylinder head gasket. Failure to do so
may result in engine damage.
NOTE: Thoroughly clean all mating surfaces with
the appropriate solvents to assure that no grease or
oil is present during assembly.
(1) Inspect cylinder head gasket and oil pan gas-
ket. If damaged, replace.
(2) Replace the front crankshaft seal (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - FRONT - INSTALLATION).
(3) Install ancillary components to timing case
cover.
(4) Apply sealant to the marked surfaces with a
bead thickness of 1.5   0.5 mm (Fig. 74).
NOTE: Install timing cover within 10 minutes after
applying sealant. Do not spread sealant bead.
NOTE: Do not seal pressurized oil galleries to the
crankcase. Sealant applied at these points is
entrained by the oil flow and blocks the oil supply
passages.
(5) Position and install timing case cover. Tighten
bolts to 20 N´m (177 lbs in) (Fig. 73).(6) Install the M8 bolts of cylinder head on timing
case cover. Tighten bolts to 20 N´m (177 lbs in) (Fig.
73).
(7) Install timing chain tensioner with new seal
(Refer to 9 - ENGINE/VALVE TIMING/TMNG BELT/
CHAIN TENSIONER&PULLEY - INSTALLATION).
(8) Position and install the oil pan. Tighten M6
bolts to 9 N´m (80 lbs in) and M8 bolts to 20 N´m
(177 lbs in).
(9) Install belt /pulley vibration damper. Tighten
M8.8 bolt in two stages, 200N´m (147 lbs ft.) then
90É, M10.9 bolt 325N´m (240 lbs ft) then 90É.
(10) Remove the engine support fixture.
(11) Install generator (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - INSTALLATION).
(12) Install the air conditioning compressor.
(13) Install the power steering pump.
(14) Install water pump (Refer to 7 - COOLING/
ENGINE/WATER PUMP - INSTALLATION).
(15) Connect coolant hose to oil-water heat
exchanger.
(16) Install high pressure fuel pump (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL PUMP -
INSTALLATION).
(17) Apply sealant to lower portion of, and install,
front cover to cylinder block. Tighten bolts to 20N´m
(177 lbs in) (Refer to 9 - ENGINE/CYLINDER HEAD
- INSTALLATION).
(18) Remove retaining lock for crankshaft/starter
ring gear.
(19) Tighten the oil drain plug to 30N´m (265 lbs
in).
(20) Install a new oil filter. tighten screw cap for
filter to 25N´m (221 lbs. in.).
(21) Install the accessory drive belt.
(22) Install the radiator assembly (Refer to 7 -
COOLING/ENGINE/RADIATOR - INSTALLATION).
(23) Install air intake hose.
(24) Fill coolant to the proper level, with the
proper coolant (Refer to 7 - COOLING/ENGINE/
COOLANT - STANDARD PROCEDURE).
(25) Fill the crankcase with the correct oil, to the
proper level. Refer to owners manual for specifica-
tions.
(26) Connect the negative battery cable.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR FAN. DO
NOT WEAR LOOSE CLOTHES.
CAUTION: DO NOT pressure test cooling system
until the engine reaches operating temperature.
Fig. 74 TIMING CHAIN COVER SEALING SURFACE
1 - TIMING CHAIN COVER
2 - SEALANT BEAD
VAENGINE 9 - 71

CAUTIONS
CAUTION: Never add R-12 to a refrigerant system
designed to use R-134a. Do not use R-12 equipment
or parts on a R-134a A/C system. These refrigerants
are not compatible and damage to the A/C system
will result.
CAUTION: Never use R-12 refrigerant oil in a A/C
system designed to use R-134a refrigerant oil.
These refrigerant oils are not compatible and dam-
age to the A/C system will result.
CAUTION: The use of A/C system sealers may
result in damage to A/C refrigerant recovery/evacu-
ation/recharging equipment and/or A/C system.
Many federal, state/provincial and local regulations
prohibit the recharge of A/C systems with known
leaks. DaimlerChrysler recommends the detection
of A/C system leaks through the use of approved
leak detectors and fluorescent leak detection dyes.
Vehicles found with A/C system sealers should be
treated as contaminated and replacement of the
entire A/C refrigerant system is recommended. A/C
systems found to be contaminated with A/C system
sealers, A/C stop-leak products or seal conditioners
voids the warranty for the A/C system.
CAUTION: Recover the refrigerant before opening
any fitting or connection. Open the fittings with
caution, even after the system has been dis-
charged. Never open or loosen a connection before
recovering the refrigerant.
CAUTION: If equipped, do not remove the second-
ary retention clip from any spring-lock coupler con-
nection while the refrigerant system is under
pressure. Recover the refrigerant before removing
the secondary retention clip. Open the fittings with
caution, even after the system has been dis-
charged. Never open or loosen a connection before
recovering the refrigerant.
CAUTION: The internal parts of the A/C system will
remain stable as long as moisture-free refrigerant
and refrigerant oil is used. Abnormal amounts of
dirt, moisture or air can upset the chemical stability.
This may cause operational troubles or even seri-
ous damage if present in more than very small
quantities. Before disconnecting a component,
clean the outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system. Keep service tools and the work area clean.
Do not open the refrigerant system or uncap areplacement component until you are ready to ser-
vice the system. Immediately after disconnecting a
component from the refrigerant system, seal the
open fittings with a cap or plug. This will prevent
contamination from entering the A/C system.
CAUTION: Refrigerant oil will absorb moisture from
the atmosphere if left uncapped. Do not open a
container of refrigerant oil until you are ready to
use it. Replace the cap on the oil container immedi-
ately after using. Store refrigerant oil only in a
clean, airtight, and moisture-free container.
CAUTION: Do not overcharge the refrigerant sys-
tem. Overcharging will cause excessive compressor
head pressure and can cause compressor noise
and A/C system failure.
DIAGNOSIS AND TESTING
REFRIGERANT SYSTEM LEAKS
WARNING: R-134a service equipment or vehicle A/C
system should not be pressure tested or leak tested
with compressed air. Mixture of air and R-134a can
be combustible at elevated pressures. These mix-
tures are potentially dangerous and may result in
fire or explosion causing property damage, per-
sonal injury or death.
Avoid breathing A/C refrigerant and lubricant vapor
or mist. Exposure may irritate eyes, nose and
throat. Use only approved service equipment meet-
ing SAE requirements to discharge R-134a system.
If accidental system discharge occurs, ventilate
work area before resuming service.
If the A/C system is not cooling properly, determine
if the refrigerant system is fully charged with
R-134a. This is accomplished by performing a Refrig-
erant System Charge Level test (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING -
DIAGNOSIS AND TESTING - REFRIGERANT SYS-
TEM CHARGE LEVEL) or by completely evacuating
and recharging the A/C system. If the A/C liquid line
pressure is found to be less than 345 kPa (50 psi)
while performing the Refrigerant System Charge
Level test, proceed to the System Empty procedure
below. If liquid line pressure is found to be greater
than 345 kPa (50 psi), proceed to the System Low
procedure. If the refrigerant system is empty or low
in refrigerant charge, a leak at any line fitting or
component seal is likely. A review of the fittings,
lines and components for oily residue is an indication
of the leak location. To detect a leak in the refriger-
ant system, perform one of the following procedures
as indicated by the symptoms.
24 - 62 PLUMBINGVA

SYSTEM EMPTY
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approximately 28 in Hg.)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE). Determine if the
system holds a vacuum for 15 minutes. If vacuum is
held, a leak is probably not present. If system will
not maintain vacuum level, proceed to Step 2.
(2) Prepare and dispense 0.284 kilograms (10
ounces) of R-134a refrigerant into the evacuated
refrigerant system (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM CHARGE) and
proceed to Step 1 of the System Low procedure.
SYSTEM LOW
(1) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(2) Operate the heating-A/C system with the
engine at idle under the following conditions for at
least five minutes.
²Doors or windows open
²Transmission in Park
²A/C-heater controls set to outside air, full cool,
panel mode, high blower and with A/C compressor
engaged
CAUTION: A leak detector only designed for R-12
refrigerant will not detect leaks in a R-134a refriger-
ant system.
(3) Shut the vehicle Off and wait 2-7 minutes.
Then use an electronic leak detector that is designed
to detect R-134a refrigerant and search for leaks. Fit-
tings, lines or components that appear to be oily usu-
ally indicate a refrigerant leak. To inspect the A/C
evaporator for leaks, insert the leak detector probe
into the drain tube opening or an air outlet. A dye for
R-134a is available to aid in leak detection. Use only
DaimlerChrysler approved refrigerant dye.
STANDARD PROCEDURE
REFRIGERANT SYSTEM SERVICE EQUIPMENT
WARNING: Eye protection must be worn when ser-
vicing an A/C refrigerant system. Turn off (rotate
clockwise) all valves on the equipment being used,
before connecting to or disconnecting from the
refrigerant system. Failure to observe these warn-
ings may result in possible personal injury.
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Referto 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
When servicing the air conditioning system, a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 must be used.
Contact an automotive service equipment supplier for
refrigerant recovery/recycling/charging equipment.
Refer to the operating instructions supplied by the
equipment manufacturer for proper care and use of
this equipment.
A manifold gauge set may be needed with some
recovery/recycling/charging equipment (Fig. 1). The
service hoses on the gauge set being used should
have manual (turn wheel), or automatic back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
Fig. 1 Manifold Gauge Set - Typical
1 - HIGH PRESSURE GAUGE
2 - VALVE
3 - VACUUM/REFRIGERANT HOSE (YELLOW W/ BLACK
STRIPE)
4 - HIGH PRESSURE HOSE (RED W/ BLACK STRIPE)
5 - LOW PRESSURE HOSE (BLUE W/ BLACK STRIPE)
6 - VALVE
7 - LOW PRESSURE GAUGE
VAPLUMBING 24 - 63

FRONTA/CSYSTEM
²LOW PRESSURE GAUGE HOSEÐThe low
pressure hose (Blue with Black stripe) attaches to
the suction line service port. This port is located on
the suction line near the dash panel.
²HIGH PRESSURE GAUGE HOSEÐThe high
pressure hose (Red with Black stripe) attaches to the
discharge line service port. This port is located on the
liquid line between the condenser and the reciver-
drier.
²RECOVERY/RECYCLING/EVACUATION/
CHARGING HOSEÐThe center manifold hose (Yel-
low, or White, with Black stripe) is used to recover,
evacuate, and charge the refrigerant system. When
the low or high pressure valves on the manifold
gauge set are opened, the refrigerant in the system
will escape through this hose.
REARA/CSYSTEM
²LOW PRESSURE GAUGE HOSEÐThe low
pressure hose (Blue with Black stripe) attaches to
the suction line service port. This port is located
within the rear A/C evaporator housing near the left
side of the evaporator, below the high-pressure ser-
vice port.
²HIGH PRESSURE GAUGE HOSEÐThe high
pressure hose (Red with Black stripe) attaches to the
liquid line service port. This port is located within
the rear A/C evaporator housing near the left side of
the evaporator, above the low-pressure service port.
²RECOVERY/RECYCLING/EVACUATION/
CHARGING HOSEÐThe center manifold hose (Yel-
low, or White, with Black stripe) is used to recover,
evacuate, and charge the refrigerant system. When
the low or high pressure valves on the manifold
gauge set are opened, the refrigerant in the system
will escape through this hose.
REFRIGERANT SYSTEM RECOVERY
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to recover the refrigerant from an R-134a refrig-
erant system. Refer to the operating instructions sup-
plied by the equipment manufacturer for the proper
care and use of this equipment.
REFRIGERANT SYSTEM EVACUATE
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be charged. If moisture and air enters the system
and becomes mixed with the refrigerant, the com-
pressor head pressure will rise above acceptable
operating levels. This will reduce the performance of
the air conditioner and damage the compressor.
Evacuating the refrigerant system will remove the
air and boil the moisture out of the system at near
room temperature. To evacuate the refrigerant sys-
tem, use the following procedure:
(1) Connect a R-134a refrigerant recovery/recy-
cling/charging station that meets SAE Standard
J2210 and a manifold gauge set to the refrigerant
system of the vehicle.
(2) Open the low and high side valves and start
the charging station vacuum pump. When the suc-
tion gauge reads 88 kPa (26 in. Hg.) vacuum or
greater, close all of the valves and turn off the vac-
uum pump.
(a) If the refrigerant system fails to reach the
specified vacuum, the system has a leak that must
be corrected. (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - DIAGNOSIS AND
TESTING - REFRIGERANT SYSTEM LEAKS)
(b) If the refrigerant system maintains the spec-
ified vacuum for five minutes, restart the vacuum
pump, open the suction and discharge valves and
evacuate the system for an additional ten minutes.
(3) Close all of the valves, and turn off the charg-
ing station vacuum pump.
(4) The refrigerant system is now ready to be
charged with R-134a refrigerant. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
REFRIGERANT SYSTEM CHARGE
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
24 - 64 PLUMBINGVA

CAUTION: A small amount of refrigerant oil is
removed from the A/C system each time the refrig-
erant system is recovered and evacuated. Before
charging the A/C system, you MUST replenish any
oil lost during the recovery process. Refer the
equipment manufacturer instructions for more infor-
mation.
After the refrigerant system has been tested for
leaks and evacuated, a refrigerant charge can be
injected into the system. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - SPECIFICA-
TIONS - CHARGE CAPACITY)
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to charge the refrigerant system with R-134a
refrigerant. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
PARTIAL CHARGE METHOD
The partial charge method is used to add a partial
charge to a refrigerant system that is low on refrig-
erant. To perform this procedure the evaporator inlet
and outlet tube temperatures are measured. The
temperature difference is measured with a tempera-
ture meter with one or two clamp-on thermocouple
probes. The difference between the evaporator inlet
and outlet tube temperatures will determine the
amount of refrigerant needed.
Before adding a partial refrigerant charge, check
for refrigerant system leaks. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - DIAGNOSIS
AND TESTING - REFRIGERANT SYSTEM LEAKS)
If a leak is found, make the necessary repairs before
attempting a full or partial refrigerant charge.
(1) Attach a manifold gauge set to the refrigerant
system service ports.
(2) Attach the two clamp-on thermocouple probes
to the inlet and outlet tubes of the evaporator coil.
²If a single thermocouple probe is used, attach
the probe to the evaporator inlet tube just before the
collar of the refrigerant line connector fitting. The
probe must make contact with the bottom surface of
the evaporator inlet tube.
²If dual thermocouple probes are used, attach
probe 1 to the evaporator inlet tube, and probe 2 to
the evaporator outlet tube. Attach both probes to the
evaporator tubes just before the collar of the refrig-erant line connector fittings. The probes must make
contact with the bottom surfaces of the evaporator
inlet and outlet tubes.
(3) Open all of the windows or doors of the passen-
ger compartment.
(4) Set the A/C button on the A/C Heater controls
to the on position, the temperature control knob in
the full cool position, select Recirculation Mode, and
place the blower motor switch in the highest speed
position.
(5) Start the engine and hold the engine idle speed
at 1,000 rpm. Allow the engine to warm up to normal
operating temperature.
(6) The compressor clutch may cycle, depending
upon ambient temperature, humidity, and the refrig-
erant system charge level.
(7) Hold the engine idle speed at 1,000 rpm.
(8) Allow three to five minutes for the refrigerant
system to stabilize, then record the temperatures of
the evaporator inlet and outlet tubes.
²If a single probe is used, record the temperature
of the evaporator inlet tube. Then remove the probe
from the inlet tube and attach it to the evaporator
outlet tube just before the collar of the refrigerant
line connector fitting. The probe must make contact
with the bottom surface of the evaporator outlet tube.
Allow the thermocouple and meter time to stabilize,
then record the temperature of the evaporator outlet
tube. Subtract the inlet tube temperature reading
from the outlet tube temperature reading.
²If dual probes are used, record the temperatures
of both the evaporator inlet and outlet tubes. Then
subtract the inlet tube temperature reading from the
outlet tube temperature reading.
(9) If the measured temperature differential is
higher than 22É C to 26É C (40É F to 47É F), add 0.4
kilograms (14 ounces) of refrigerant.
(10) Allow three to five minutes for the refrigerant
system to stabilize, then take a second set of thermo-
couple measurements. Record the temperature differ-
ence to determine if an additional charge is required.
(11) Record the compressor discharge pressure. If
the reading is higher than the pressure shown in the
Compressor Discharge Pressure Chart, the system
could be overcharged. If the reading is equal to, or
lower, than the pressure shown in the chart, continue
with this procedure.
Compressor Discharge Pressure Chart
Ambient Tempera-
ture16ÉC
(60ÉF)21ÉC
(70ÉF)27ÉC
(80ÉF)32ÉC
(90ÉF)38ÉC
(100ÉF)43ÉC
(110ÉF)
Compressor Dis-
charge Pressure1378 kPa
(200 psi)1516 kPa
(220 psi)1723 kPa
(250psi)1930 kPa
(280 psi)2206 kPa
(320 psi)2413 kPa
(350 psi)
VAPLUMBING 24 - 65