fuse DODGE RAM 2001 Service Repair Manual

A/C COMPRESSOR CLUTCH
DESCRIPTION
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil, a hub bearing and pul-
ley assembly, and a clutch plate (Fig. 4). The
electromagnetic coil unit and the hub bearing and
pulley assembly are each retained on the nose of the
compressor front housing with snap rings. The clutch
plate is mounted to the compressor shaft and secured
with a nut.
OPERATION
The compressor clutch assembly provides the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch into contact with the pulley and drives the
compressor shaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is
part of the pulley. The compressor clutch and coil are
the only serviced parts on the compressor.
The compressor clutch engagement is controlled by
several components: the a/c heater mode control
switch, the a/c low pressure switch, the a/c high pres-
sure switch, the compressor clutch relay, and the
Powertrain Control Module (PCM). The PCM may
delay compressor clutch engagement for up to thirty
seconds. Refer to Electronic Control Modules for
more information on the PCM controls.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The battery must
be fully-charged before performing the following
tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the a/c heater mode control switch in any
A/C mode, and the blower motor switch in the lowest
speed position, start the engine and run it at normal
idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRB IIItscan tool and (Refer to
Appropriate Diagnostic Information) for testing of the
compressor clutch circuit. The following components
must be checked and repaired as required before you
can complete testing of the clutch coil:
²Fuses in the junction block and the Power Dis-
tribution Center (PDC)
²A/C Heater mode control switch
²Compressor clutch relay
²A/C High Pressure Switch
²A/C Low Pressure Switch
²Powertrain Control Module (PCM).
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is 2.0 to 3.9
amperes with the electrical system voltage at 11.5 to
12.5 volts. This should only be checked with the work
area temperature at 21É C (70É F). If system voltage
is more than 12.5 volts, add electrical loads by turn-
ing on electrical accessories until the system voltage
drops below 12.5 volts.
(a) If the clutch coil current reading is four
amperes or more, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
STANDARD PROCEDURE - A/C COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C Heater control to the
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
to 2000 rpm. This procedure (burnishing) will seat
Fig. 4 COMPRESSOR CLUTCH - TYPICAL
1 - CLUTCH PLATE
2 - SHAFT KEY
3 - PULLEY
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
BR/BECONTROLS 24 - 13

(1) The relay common feed terminal cavity (30) is
connected to fused battery feed. There should be bat-
tery voltage at the cavity for relay terminal 30 at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the compressor clutch coil. There should
be continuity between this cavity and the A/C com-
pressor clutch relay output circuit cavity of the com-
pressor clutch coil wire harness connector. If OK, go
to Step 4. If not OK, repair the open circuit as
required.
(4) The relay coil battery terminal (86) is con-
nected to the fused ignition switch output (run/start)
circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
open circuit to the fuse in the junction block as
required.
(5) The coil ground terminal cavity (85) is switched
to ground through the Powertrain Control Module
(PCM). There should be continuity between this cav-
ity and the A/C compressor clutch relay control cir-
cuit cavity of the PCM wire harness connector C
(gray) at all times. If not OK, repair the open circuit
as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 17).(3) Refer to the label on the PDC for compressor
clutch relay identification and location.
(4) Unplug the compressor clutch relay from the
PDC.
INSTALLATION
(1) Install the compressor clutch relay by aligning
the relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
A/C HEATER CONTROL
DESCRIPTION
Both the heater-only and a/c heater systems use a
combination of electrical and vacuum controls. These
controls provide the vehicle operator with a number
of setting options to help control the climate and
comfort within the vehicle. Refer to the owner's man-
ual in the vehicle glove box for more information on
the features, use, and suggested operation of these
controls.
OPERATION
The heater-only or a/c heater control panel is
located to the right of the instrument cluster on the
instrument panel. The control panel contains a rota-
ry-type temperature control knob, a rotary-type mode
control switch knob, and a rotary-type blower motor
speed switch knob. On models with the optional
heated mirror system, a momentary push button
switch and indicator lamp are located near the bot-
Fig. 16 COMPRESSOR CLUTCH RELAY
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 17 POWER DISTRIBUTION CENTER
1 - COVER
2 - POWER DISTRIBUTION CENTER
24 - 18 CONTROLSBR/BE
A/C COMPRESSOR CLUTCH RELAY (Continued)

(2) Unplug the wire harness connector from the a/c
low pressure switch on the top of the accumulator
(Fig. 20).
(3) Unscrew the a/c low pressure switch from the
fitting on the top of the accumulator.
(4) Remove the O-ring seal from the accumulator
fitting and discard.
INSTALLATION
(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the accumulator fitting.
Use only the specified O-rings as they are made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/REFRIGERANT
OIL - DESCRIPTION)
(2) Install and tighten the a/c low pressure switch
on the accumulator fitting. The switch should be
hand-tightened onto the accumulator fitting.
(3) Plug the wire harness connector into the a/c
low pressure switch.
(4) Connect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay is an International Stan-
dards Organization (ISO)-type relay. The relay is an
electromechanical device that switches battery cur-
rent from a fuse in the Power Distribution Center
(PDC) directly to the blower motor. The relay is ener-
gized when the relay coil is provided a voltage signal
by the ignition switch. This arrangement reduces the
amount of battery current that must flow through
the ignition switch.
OPERATION
The blower motor relay control circuit is protected
by a fuse located in the junction block. When the
relay is de-energized, the blower motor receives no
battery current.
The blower motor relay is located in the PDC in
the engine compartment. Refer to the PDC label for
blower motor relay identification and location.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RELAY
RELAY TEST
The blower motor relay (Fig. 21) is located in the
Power Distribution Center (PDC). Remove the blower
motor relay from the PDC 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 7565 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, see Relay Circuit Test below. If not
OK, replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed directly from a fuse
in the Power Distribution Center (PDC), and should
be hot at all times. Check for battery voltage at the
PDC cavity for relay terminal 30. If OK, go to Step 2.
If not OK, repair the open circuit to the PDC fuse as
required.
Fig. 20 ACCUMULATOR AND A/C LOW PRESSURE
SWITCH
1 - CLIP
2 - BRACKET
3 - SCREW
4 - BAND
5 - ACCUMULATOR
6 - TO SUCTION LINE
7 - A/C LOW PRESSURE SWITCH
8 - FROM EVAPORATOR OUTLET
24 - 22 CONTROLSBR/BE
A/C LOW PRESSURE SWITCH (Continued)

(2) The relay normally closed terminal cavity (87A)
is not used for this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the blower motor. When the relay is
energized, terminal 87 is connected to terminal 30
and provides full battery current to the blower motor
feed circuit. There should be continuity between the
PDC cavity for terminal 87 and the blower motor
relay output circuit cavity of the blower motor wire
harness connector at all times. If OK, go to Step 4. If
not OK, repair the open circuit to the blower motor
as required.
(4) The coil battery terminal cavity (86) is con-
nected to the ignition switch. When the ignition
switch is placed in the On position, fused ignition
switch output is directed from a fuse in the junction
block to the relay electromagnetic coil to energize the
relay. There should be battery voltage at the PDC
cavity for relay terminal 86 with the ignition switch
in the On position. If OK, go to Step 5. If not OK,
repair the open circuit to the junction block fuse as
required.
(5) The coil ground terminal cavity (85) is con-
nected to ground. This terminal supplies the ground
for the relay electromagnetic coil. There should be
continuity between the PDC cavity for relay terminal
85 and a good ground at all times. If not OK, repair
the open circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 22).
(3) Refer to the label on the PDC for blower motor
relay identification and location.
(4) Unplug the blower motor relay from the PDC.
INSTALLATION
(1) Install the blower motor relay by aligning the
relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
The blower motor resistor is mounted to the bot-
tom of the HVAC housing, under the instrument
panel and just inboard of the blower motor. It can be
accessed without removing any other components.
OPERATION
The resistor has multiple resistor wires, each of
which will change the resistance in the blower motor
ground path to change the blower motor speed. The
blower motor switch directs the ground path through
the correct resistor wire to obtain the selected blower
motor speed.
Fig. 21 BLOWER MOTOR RELAY
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 22 POWER DISTRIBUTION CENTER
1 - COVER
2 - POWER DISTRIBUTION CENTER
BR/BECONTROLS 24 - 23
BLOWER MOTOR RELAY (Continued)

motor speeds, but can only be turned off by selecting
the Off position with the heater-only or a/c heater
control switch knob.
OPERATION
The blower motor switch directs the blower motor
ground path through the mode control switch to the
blower motor resistor, or directly to ground, as
required to achieve the selected blower motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or a/c
heater control unit must be replaced. The blower
motor switch knob is serviced separately.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
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.
(1) Check for battery voltage at the fuse in the
Power Distribution Center (PDC). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the a/c heater control from the instrument
panel. (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS/A/C HEATER CONTROL -
REMOVAL) Check for continuity between the ground
circuit cavity of the a/c heater control wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 3. If not OK, repair the open
circuit to ground as required.
(3) With the a/c heater control wire harness con-
nector unplugged, place the a/c heater mode control
switch knob in any position except the Off position.
Check for continuity between the ground circuit ter-
minal and each of the blower motor driver circuit ter-
minals of the a/c heater control as you move the
blower motor switch knob to each of the four speed
positions. There should be continuity at each drivercircuit terminal in only one blower motor switch
speed position. If OK, test and repair the blower
driver circuits between the a/c heater control connec-
tor and the blower motor resistor as required. If not
OK, replace the faulty a/c heater control unit.
REMOVAL
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or a/c
heater control unit must be replaced. (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL) The blower motor
switch knob is serviced separately.
BLEND DOOR ACTUATOR
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.
(1) Turn the ignition switch to the run position.
(2) Locate the temperature control knob in the mid
(12 o'clock) position.
(3) Turn the ignition switch to the off position.
(4) Disconnect and isolate the battery negative
cable.
(5) Remove the instrument panel from the vehicle.
Refer to Instrument Panel System for the procedures.
(6) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(7) Unplug the wire harness connector from the
blend door actuator (Fig. 24).
(8) Remove the two mounting screws which secure
the actuator to the housing.
(9) Slide the blend door actuator off the blend door
shaft.
NOTE: A black plastic coupler may be attached to
the blend door shaft. Remove the coupler and
inspect for damage. Reinstall if there is no damage
found.
BR/BECONTROLS 24 - 25
BLOWER MOTOR SWITCH (Continued)

REMOVAL - PANEL OUTLET BARRELS
WARNING: THE PANEL OUTLET BARRELS
INSTALLED IN THE PASSENGER SIDE AIRBAG
DOOR PANEL OUTLET HOUSINGS MUST NEVER
BE REINSTALLED FOLLOWING REMOVAL FOR ANY
REASON. THEY MUST BE REPLACED WITH NEW
BARRELS. FAILURE TO OBSERVE THIS WARNING
COULD RESULT IN OCCUPANT INJURIES UPON
AIRBAG DEPLOYMENT.
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry near the center of either
side of the panel outlet barrel to release the snap-fit
pivots on the barrel from the pivot pins in the outlet
housing of the passenger side airbag module or the
instrument cluster bezel (Fig. 2).
(2)
Remove the barrel from the panel outlet housing.
INSTALLATION - DEMISTER GRILLES
(1) To install the demister grille, position the grille
in the opening of the instrument panel top cover and
press inwards firmly and evenly near the center of
both sides of the grille until it snaps into place.
INSTALLATION - PANEL OUTLET BARRELS
WARNING: THE PANEL OUTLET BARRELS INSTALLED
IN THE PASSENGER SIDE AIRBAG DOOR PANEL OUT-
LET HOUSINGS MUST NEVER BE REINSTALLED FOL-
LOWING REMOVAL FOR ANY REASON. THEY MUST
BE REPLACED WITH NEW BARRELS. FAILURE TO
OBSERVE THIS WARNING COULD RESULT IN OCCU-
PANT INJURIES UPON AIRBAG DEPLOYMENT.
(1) To install a new panel outlet barrel, position
the barrel in the outlet housing and press inwards
firmly and evenly near the center of both sides of the
panel outlet barrel until the pivots snap into place.
BLOWER MOTOR
DESCRIPTION
The blower motor and blower wheel are located in
the passenger side end of the HVAC housing, below
the glove box. The blower motor controls the velocity
of the air flowing through the HVAC housing by spin-
ning a squirrel cage-type blower wheel within the
housing at the selected speed. The blower motor and
blower wheel can be serviced from the passenger
compartment side of the housing.
OPERATION
The blower motor will only operate when the igni-
tion switch is in the On position, and the a/c heater
mode control switch knob is in any position, except
Off. The blower motor receives a fused battery feed
through the blower motor relay whenever the igni-
tion switch is in the On position.
The blower motor battery feed circuit is protected
by a fuse in the Power Distribution Center (PDC).
The blower motor relay control circuit is protected by
a fuse in the junction block. Blower motor speed is
controlled by regulating the ground path through the
a/c heater mode control switch, the blower motor
switch, and the blower motor resistor.
The blower motor and blower wheel cannot be
repaired and, if faulty or damaged, they must be
replaced. The blower motor and blower wheel may be
serviced separately, although if the motor is to be
replaced, a blower wheel will come as part of a pre-
balanced assembly.
Fig. 2 PANEL OUTLET BARRELS
1 - DEFROSTER OUTLETS
2 - DEMISTER OUTLET GRILLE
3 - PANEL OUTLET BARRELS
4 - DEMISTER OUTLET GRILLE
24 - 32 DISTRIBUTIONBR/BE
AIR OUTLETS (Continued)

DIAGNOSIS AND TESTING - BLOWER MOTOR
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPT-
ING ANY STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE, THEN WAIT TWO MIN-
UTES FOR THE AIRBAG SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD RESULT
IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). Possible causes of
an inoperative blower motor include:
²Faulty fuse
²Faulty blower motor circuit wiring or wire har-
ness connectors
²Faulty blower motor resistor
²Faulty blower motor relay
²Faulty blower motor switch
²Faulty a/c heater mode control switch
²Faulty blower motor.
Possible causes of the blower motor not operating
in all speeds include:
²Faulty fuse
²Faulty blower motor switch
²Faulty blower motor resistor
²Faulty blower motor relay
²Faulty blower motor circuit wiring or wire har-
ness connectors.
VIBRATION
Possible causes of blower motor vibration include:
²Improper blower motor mounting
²Improper blower wheel mounting
²Blower wheel out of balance or deformed
²Blower motor faulty.
NOISE
To verify that the blower is the source of the noise,
unplug the blower motor wire harness connector and
operate the HVAC system. If the noise goes away,
possible causes include:
²Foreign material in the HVAC housing
²Improper blower motor mounting
²Improper blower wheel mounting
²Blower motor faulty.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.(2) Disconnect the blower motor cooling tube from
the nipple on the blower motor housing (Fig. 3).
(3) Disengage the blower motor wire harness from
the wire harness retainer.
(4) Unplug the blower motor wire harness connec-
tor from the HVAC housing wire harness.
(5) Remove the three screws that secure the
blower motor and blower wheel assembly to the
HVAC housing.
(6) Lower the blower motor and wheel assembly,
and cover, from the HVAC housing.
(7)
Remove the blower wheel retainer clip and
remove the wheel from the blower motor shaft (Fig. 4).
INSTALLATION
(1) If installing the blower motor wheel only, press
the blower wheel hub onto the blower motor shaft.
Be sure the flat on the blower motor shaft is indexed
to the flat on the inside of the blower wheel hub.
(2) Install the retainer clip over the blower wheel
hub. The ears of the retainer clip must be indexed
over the flats on the blower motor shaft and blower
wheel hub.
(3) Be certain that the blower motor seal is
installed on the blower motor housing (Fig. 5).
(4) Install the blower motor and wheel assembly,
and cover in the HVAC housing with three mounting
screws. Tighten the mounting screws to 2.2 N´m (20
in. lbs.).
Fig. 3 BLOWER MOTOR REMOVE/INSTALL
1 - BLOWER MOTOR HOUSING
2 - COOLING TUBE
3 - ELECTRICAL CONNECTOR
BR/BEDISTRIBUTION 24 - 33
BLOWER MOTOR (Continued)

compressor is engaged and circulating refrigerant
through the evaporator coil tubes.
OPERATION
Refrigerant enters the evaporator from the fixed
orifice tube as a low-temperature, low-pressure liq-
uid. As air flows over the fins of the evaporator, the
humidity in the air condenses on the fins, and the
heat from the air is absorbed by the refrigerant. Heat
absorption causes the refrigerant to boil and vapor-
ize. The refrigerant becomes a low-pressure gas when
it leaves the evaporator.
The evaporator coil cannot be repaired and, if
faulty or damaged, it must be replaced.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Remove the HVAC housing from the vehicle,
and disassemble the housing halves. (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL) (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - DISASSEMBLY)
(2) Lift the a/c evaporator out of the HVAC hous-
ing (Fig. 11).
INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)(Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(1) Insert the evaporator coil into the bottom of the
HVAC housing.
(2) Reassemble and reinstall the HVAC housing in
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING -
ASSEMBLY) (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/HVAC HOUSING -
INSTALLATION)
NOTE: If the evaporator is replaced, add 60 millili-
ters (2 fluid ounces) of refrigerant oil to the refrig-
erant system.
A/C ORIFICE TUBE
DESCRIPTION
The fixed orifice tube is installed in the liquid line
between the outlet of the condenser and the inlet of
the evaporator. The fixed orifice tube is only serviced
as an integral part of the liquid line.
OPERATION
The inlet end of the fixed orifice tube has a nylon
mesh filter screen, which filters the refrigerant and
helps to reduce the potential for blockage of the
metering orifice by refrigerant system contaminants
(Fig. 12). The outlet end of the tube has a nylon
mesh diffuser screen. The O-rings on the plastic body
of the fixed orifice tube seal the tube to the inside of
the liquid line and prevent the refrigerant from
bypassing the fixed metering orifice.
The fixed orifice tube is used to meter the flow of
liquid refrigerant into the evaporator coil. The high-
pressure liquid refrigerant from the condenser
expands into a low-pressure liquid as it passes
through the metering orifice and diffuser screen of
the fixed orifice tube.
The fixed orifice tube cannot be repaired and, if
faulty or plugged, the liquid line assembly must be
replaced.
Fig. 11 A/C EVAPORATOR LOCATION IN HVAC
HOUSING (UPSIDE DOWN)
1 - EVAPORATOR LOCATION
2 - BOTTOM HALF OF HVAC HOUSING
3 - TOP HALF OF HVAC HOUSING
BR/BEPLUMBING 24 - 53
A/C EVAPORATOR (Continued)

DIAGNOSIS AND TESTING - FIXED ORIFICE
TUBE
The fixed orifice tube can be checked for proper
operation using the following procedure. However,
the fixed orifice tube is only serviced as a part of the
liquid line unit. If the results of this test indicate
that the fixed orifice tube is obstructed or missing,
the entire liquid line unit must be replaced.
WARNING: THE LIQUID LINE BETWEEN THE CON-
DENSER OUTLET AND THE FIXED ORIFICE TUBE
CAN BECOME HOT ENOUGH TO BURN THE SKIN.
USE EXTREME CAUTION WHEN PERFORMING THE
FOLLOWING TEST.
(1) Confirm that the refrigerant system is properly
charged. (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING - A/C PER-
FORMANCE)
(2) Start the engine. Turn on the air conditioning
system and confirm that the compressor clutch is
engaged.
(3) Allow the air conditioning system to operate for
five minutes.
(4) Lightly and cautiously touch the liquid line
near the condenser outlet at the front of the engine
compartment. The liquid line should be hot to the
touch.
(5) Touch the liquid line near the evaporator inlet
at the rear of the engine compartment. The liquid
line should be cold to the touch.
(6) If there is a distinct temperature differential
between the two ends of the liquid line, the orifice
tube is in good condition. If there is little or no
detectable temperature differential between the two
ends of the liquid line, the orifice tube is obstructed
or missing and the liquid line must be replaced.
REMOVAL
The fixed orifice tube is located in the liquid line,
between the condenser and the evaporator coil. If the
fixed orifice tube is faulty or plugged, the liquid line
assembly must be replaced. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/LIQUID LINE
- REMOVAL)
ACCUMULATOR
DESCRIPTION
The accumulator is mounted in the engine com-
partment between the a/c evaporator outlet tube and
the compressor inlet.
OPERATION
Refrigerant enters the accumulator canister as a
low pressure vapor through the inlet tube. Any liq-
uid, oil-laden refrigerant falls to the bottom of the
canister, which acts as a separator. A desiccant bag is
mounted inside the accumulator canister to absorb
any moisture which may have entered and become
trapped within the refrigerant system (Fig. 13).
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Remove the a/c low pressure switch from the
accumulator. (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS/A/C LOW PRESSURE
SWITCH - REMOVAL)
(4) Loosen the screw that secures the accumulator
retaining band to the support bracket on the dash
panel (Fig. 20).
(5) Disconnect the suction line refrigerant line fit-
ting from the accumulator outlet. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
Install plugs in, or tape over all of the opened refrig-
erant line fittings.
(6) Disconnect the accumulator inlet refrigerant
line fitting from the evaporator outlet. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
Fig. 12 FIXED ORIFICE TUBE - TYPICAL
1 - DIFFUSER SCREEN
2 - ªOº RINGS
3 - INLET FILTER SCREEN
4 - ORIFICE
24 - 54 PLUMBINGBR/BE
A/C ORIFICE TUBE (Continued)

Items found requiring adjustment and/or repair
should be corrected before delivery of the vehicle.
NOTE: It is the dealer's responsibility to protect
new vehicles from damage and deterioration prior
to retail delivery both before and after new vehicle
preparation.
The information includes the following features:
Inspection points are cross-referenced to the New
Vehicle Preparation Form as follows:
²Titles indicate the general area being inspected
or the types of checks being made (i.e., underhood,
body-exterior, road test, etc.).
²Sub-Titles identify the types of items to be
inspected in that area (i.e., lines/hoses, wiring, etc.).
Procedures follow a logical order to prevent dupli-
cation and wasted effort.
Tips to help you do a better job are found as
NOTES.
RECEIVING
INSPECTION
The following procedures are recommended for
your own protection upon receipt of new vehicles.
When a new car is delivered by the carrier, it should
be inspected to ensure that it is in good condition
and to determine if there is any shortage or transpor-
tation damage.
EXTERIOR
Upon receipt of a new vehicle, check immediately
for:
²Under carriage damage
²Chipped or cracked windshield, broken windows,
and loose or missing moldings and name-plates
²Dents, scrapes, scratches, chips, dirt in paints or
other damage to the body exterior
²Damaged or missing side view mirror(s)
²Missing wheel nuts
²Broken or missing lenses
²Chafing, bruises, cuts, or scrapes on tire side-
walls or tread
²Missing underhood items
²Missing fuel filler cap
²Shipped loose items-license plate bracket, spare
tire, jack and tire wrench, radio antenna, floor mats,
wheel covers, cargo nets, fuses and other items²Ensure that IOD fuse is removed
²Check battery test indicator when easily visible,
or use voltmeter (battery must be at 12.4 volts or
greater). Charge to ensure green dot-visibility, per-
manent damage may occur if battery remains in a
discharged state for any length of time.
INTERIOR
Check interior items such as:
²Rearview mirror
²Accessory control knobs
²Smokers package items
²Keys
²Radio
²Special equipment items listed on shipper
²Owner's Manual and Consumer information Bro-
chures (normally stored in the glove box).
²Cuts, abrasions or stains on interior trim.
NOTE: Remember a careful look at new vehicles
when they are received may prevent problems when
preparing vehicles for delivery to your customers.
MAJOR INSPECTION POINTS
(1) Check operation of hood latch and safety catch-
adjust as required.
(2) Check all fluids for proper level and top off
with the proper fluid as required-engine oil, auto-
matic transmission fluid, brake master cylinder,
clutch master cylinder, power steering, windshield
washer, and cooling system. (Vehicle must be at nor-
mal operating temperature for some of these checks.)
(3) Check brake, clutch, fuel, and power steering
lines and hoses for leaks and clearance from moving
and hot objects-reroute to the proper location and
tighten as required.
(4) Check battery state of charge-recharge if neces-
sary, to ensure green dot is visible or instrument
panel voltmeter indicates 12.4 volts or greater.
(5) Check routing and connections of underhood
wiring, vacuum hoses, refrigerant lines and coolant
hoses for leaks, loose connections and clearance from
moving objects reroute and tighten connections as
required. Install IOD fuse on applicable vehicles.
NOTE: Reset radio, clock, compass, etc., after
installing, if vehicle is being delivered.
BR/BENEW VEHICLE PREPARATION 30 - 3
INTRODUCTION (Continued)