2000 DODGE NEON engine

HEATER-A/C VACUUM SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO FORCED AIR IN
HEAT POSITION1. Vacuum line pinched or
leaking.
2. Faulty heat defroster or
mode door.
3. Faulty selector switch.
4. Vacuum check valve.1. Locate and repair vacuum leak or pinched line.
2. Test actuators and door operation. Repair as
necassary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
NO FORCED AIR IN
PANEL POSITION1. Vacuum line pinched or
leaking.
2. Faulty mode door.
3. Faulty selector switch.
4. Vacuum check valve.1. Locate and repair vacuum leak or pinched line.
2. Test actuator and door operation. Repair as
necessary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
NO FORCED AIR IN
DEFROST POSITION1. Vacuum line pinched or
leaking.
2. Faulty heat, defroster, or
mode door.
3. Faulty selector switch.
4. Vacuum check valve.1. Locate and repair vacuum leak or pinched line.
2. Test actuators and door operation. Repair as
necessary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
ONE-WAY CHECK VALVE
(1) Disconnect the heater-A/C vacuum supply
(Black) tube in the engine compartment. This tube
passes through an opening in the dash panel.
(2) Remove the one-way vacuum check valve. The
valve is located on the (Black) vacuum supply hose at
the brake power booster.
(3) Connect the test set vacuum supply hose to the
heater side of the valve. When connected to this side
of the check valve, no vacuum should pass and the
test set gauge should return to the 27 kPa (8 in. Hg.)
setting. If OK, go to step Step 4. If not OK, replace
the faulty valve.
(4) Connect the test set vacuum supply hose to the
engine vacuum side of the valve. When connected to
this side of the check valve, vacuum should flow
through the valve without restriction. If not OK,
replace the faulty valve.
HEATER-A/C CONTROLS
The operation of the Circulation door can be
viewed by removing the blower motor and looking up
into the unit inlet. See Blower Motor Wheel and
Assembly removal and installation in this section for
service procedures.
(1) Connect the test set vacuum probe to the heat-
er-A/C vacuum supply (Black) hose in the engine
compartment. Position the test set gauge so that it
can be viewed from the passenger compartment.
(2) Start with the Mode control in the Panel posi-
tion and the Circulation control in the Outside-air
position.
(3) Move the Circulation control to the Recircula-
tion position (the Circulation door should move intothe Recirculation position). After a short pause move
the Mode control to the Defrost position (the Circula-
tion door should move to the Outside-air position).
The test gauge should return to the calibrated set-
ting of 27 kPa (8 in. Hg.) after each selection is
made. If the gauge cannot achieve the calibrated set-
ting, the vacuum circuit or a component has a leak.
(4) If the gauge achieves the calibrated setting but
the door does not move, there is either a pinched vac-
uum line or a failed actuator.
LOCATING VACUUM LEAKS
(1) Connect the test vacuum probe to the vehicles
(Black) supply hose. Position the vacuum test gauge
so it can be viewed from the passenger compartment.
(2) Place the Mode in the Panel position and the
Circulation control in the Recirculation position.
(3) Remove the center instrument panel bezel.
(4) Remove the center vent duct.
(5) Remove and block the Supply (Black) vacuum
line at the control. The test gauge should return to
the calibrated setting of 27 kPa (8 in. Hg). If not,
there is a leak in the Supply line.
(6) If there is no leak in the Supply line, reconnect
it to the Control and remove the Actuator Feed (Red)
line from the Control. Block the vacuum connection
on the Control from where the line was removed. The
test gauge should return to the calibrated setting of
27 kPa (8 in. Hg.). If not, there is a leak in the Con-
trol.
(7) If there is no leak in the Supply line or the
Control, reconnect the Actuator Feed (Red) line to the
control. Remove and block the Actuator Feed (Red)
line at the Actuator. The actuator vacuum port is
accessible behind and above the Glove Box. The test
24 - 16 HEATING AND AIR CONDITIONINGPL
DIAGNOSIS AND TESTING (Continued)

CAUTION: Do not overcharge refrigerant system,
as excessive compressor head pressure can cause
noise and system failure.
After the system has been tested for leaks and
evacuated, a refrigerant (R-134a) charge can be
injected into the system.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) If using a separate vacuum pump close all
valves before disconnecting pump. Connect manifold
gauge set to the A/C service ports (Fig. 16).
NOTE: The air conditioning system in this vehicle
holds (27 oz. or 1.69 lbs.) of R-134a refrigerant.
(2) Measure refrigerant (refer to capacities). Refer
to the instructions provided with the equipment
being used.
(3) Verify engine is shut off. Open the suction and
discharge valves. Open the charge valve to allow the
refrigerant to flow into the system. When the trans-
fer of refrigerant has stopped, close the suction and
discharge valve.
(4) If all of the charge did not transfer from the
dispensing device, put vehicle controls into the fol-
lowing mode:
²Automatic transaxle in park or manual tran-
saxle in neutral
²Engine idling at 700 rpm
²A/C control set in 100 percent outside air
²Panel mode
²Blower motor ON high speed
²Vehicle windows closed
If the A/C compressor does not engage, test the
compressor clutch control circuit and correct any fail-
ure. Refer to Group 8W, Wiring Diagrams.
(5) Open the suction valve to allow the remaining
refrigerant to transfer to the system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.
(6) Close all valves and test the A/C system perfor-
mance.
(7) Disconnect the charging station or manifold
gauge set. Install the service port caps.
EVACUATING REFRIGERANT SYSTEM
NOTE: Special effort must be used to prevent mois-
ture from entering the A/C system oil. Moisture in
the oil is very difficult to remove and will cause a
reliability problem with the compressor.If a compressor designed to use R-134a refrigerant
is left open to the atmosphere for an extended period
of time. It is recommended that the refrigerant oil be
drained and replaced with new oil or a new compres-
sor be used. This will eliminate the possibility of con-
taminating the refrigerant system.
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be filled. Moisture and air mixed with the refrig-
erant will raise the compressor head pressure above
acceptable operating levels. This will reduce the per-
formance of the air conditioner and damage the com-
pressor. Moisture will boil at near room temperature
when exposed to vacuum. To evacuate the refrigerant
system:
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a suitable charging station, refrigerant
recovery machine, and a manifold gauge set with
vacuum pump (Fig. 17).
(2) Open the suction and discharge valves and
start the vacuum pump. The vacuum pump should
run a minimum of 45 minutes prior to charge to
eliminate all moisture in system. When the suction
gauge reads -88 kPa (- 26 in. Hg) vacuum or greater
for 45 minutes, close all valves and turn off vacuum
pump. If the system fails to reach specified vacuum,
the refrigerant system likely has a leak that must be
corrected. If the refrigerant system maintains speci-
fied vacuum for at least 30 minutes, start the vac-
uum pump, open the suction and discharge valves.
Fig. 17 Refrigerant Recovery Machine Hookup -
Typical
1 ± LOW SIDE CONNECTOR
2 ± HIGH SIDE CONNECTOR
3 ± TO MANIFOLD SET
24 - 18 HEATING AND AIR CONDITIONINGPL
SERVICE PROCEDURES (Continued)

(1) Discharge refrigerant system using recovery/re-
cycling equipment if charge is present.
(2) Disconnect refrigerant lines from A/C compres-
sor. Cap the open lines to prevent moisture from
entering system.
(3) Remove compressor from vehicle.
(4) From suction port on top of compressor, drain
lubricant from compressor.
(5) Add system capacity minus the capacity of
components that have not been replaced. Refer to the
Lubricant Capacity Chart. Add lubricant through the
suction port on compressor. This is not to exceed 180
ml (6.10 oz.) in total.
(6) Install compressor and connect refrigerant
lines. Then evacuate and charge refrigerant system.
SYSTEM LEAK CHECKING
WARNING: R-134a SERVICE EQUIPMENT OR VEHI-
CLE A/C SYSTEM SHOULD NOT BE PRESSURE
TESTED OR LEAK TESTED WITH COMPRESSED
AIR. MIXTURE OF AIR and R-134a CAN BE COM-
BUSTIBLE AT ELEVATED PRESSURES. THESE MIX-
TURES ARE POTENTIALLY DANGEROUS AND MAY
RESULT IN FIRE OR EXPLOSION CAUSING INJURY
OR PROPERTY DAMAGE.
AVOID BREATHING A/C REFRIGERANT AND
LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.
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 system
Charge Level-Check or Fill. If while performing this
test A/C liquid line pressure is less than 345 kPa (50
psi) proceed to Empty Refrigerant System Leak Test.
If liquid line pressure is greater than 345 kPa (50
psi) proceed to low refrigerant level leak test. 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 refrigerant system, perform
one of the following procedures as indicated by the
symptoms.
EMPTY REFRIGERANT SYSTEM LEAK TEST
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approx. 28 in Hg.). Deter-
mine if the system holds a vacuum for 15 minutes. If
vacuum is held, a leak is probably not present. If sys-tem will not maintain vacuum level, proceed with
this procedure.
(2) Prepare a.284 Kg. (10 oz.) refrigerant charge to
be injected into the system.
(3) Connect and dispense.284 Kg. (10 oz.) of refrig-
erant into the evacuated refrigerant system.
(4) Proceed to Step 2 of Low Refrigerant Level
Leak Test.
LOW REFRIGERANT LEVEL LEAK TEST
(1) Determine if there is any (R-134a) refrigerant
in the system.
(2) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes with the system
set to the following:
²Transaxle in Park
²Engine Idling at 700 rpm
²A/C Controls Set in 100 percent outside air
²Blower switch in the high A/C position
²A/C in the ON position
²Open all windows
CAUTION: A leak detector designed for R-12 refrig-
erant (only) will not detect leaks in a R-134a refrig-
erant system.
(4) Shut off the vehicle and wait 2 to 7 minutes.
Then use an Electronic Leak Detector that is
designed to detect R-134a type refrigerant and search
for leaks. Fittings, lines, or components that appear
to be oily usually indicates a refrigerant leak. To
inspect the evaporator core for leaks, insert the leak
detector probe into the drain tube opening or a heat
duct. A R-134a dye is available to aid in leak detec-
tion, use only Chrysler approved refrigerant dye.
If a thorough leak check has been completed with-
out indication of a leak, proceed to System Charge
Level.
REMOVAL AND INSTALLATION
A/C FILTER/DRIER
The filter/drier is mounted in a rubber grommet on
the right side of the engine compartment. The refrig-
erant must be recovered from the A/C system before
replacing the filter/drier assembly.
WARNING: THE REFRIGERATION SYSTEM MUST
BE COMPLETELY RECOVERED BEFORE PRO-
CEEDING WITH THIS OPERATION.
24 - 20 HEATING AND AIR CONDITIONINGPL
SERVICE PROCEDURES (Continued)

BLOWER MOTOR RESISTOR
CAUTION: Stay clear of the blower motor and resis-
tor block (Hot). Do not operate the blower motor
with the resistor block removed.
REMOVAL
(1) Remove windshield wipers.
(2) Remove cowl top screen.
(3) Disconnect the resistor block wiring connector
(Fig. 22).
(4) Remove/unsnap resistor block from vehicle.
INSTALLATION
For installation, reverse the above procedures.
BLOWER MOTOR WHEEL
The blower motor wheel is only serviced with the
blower motor. The wheel and the motor are balanced
as an assembly. If the blower motor wheel requires
replacement, the blower motor must also be replaced.
Refer to blower motor for replacement procedure.
COMPRESSOR
CAUTION: Add only new lubricant when system
requires additional lubricant. Do not use old
reclaimed lubricant.
REMOVAL
The A/C compressor may be unbolted and reposi-
tioned without discharging the refrigerant system.
Discharging is not necessary if removing the com-
pressor clutch/coil assembly, engine, cylinder head, or
alternator.
WARNING: REFRIGERANT PRESSURES REMAIN
HIGH EVEN THOUGH THE ENGINE MAY BE
TURNED OFF. DO NOT TWIST OR KINK THE
REFRIGERANT LINES WHEN REMOVING A FULLY
CHARGED COMPRESSOR. SAFETY GLASSES
MUST BE WORN.
(1) Disconnect battery negative cable.
(2) Loosen and remove drive belts, refer to Group
7, Engine Cooling.
(3) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system. If the com-
pressor is being replaced.
(4) Disconnect compressor clutch wire lead.
(5) Remove refrigerant lines from compressor, if
necessary (Fig. 23).
(6) If system is left open place plug/cap over open
lines.
(7) Remove compressor attaching bolts (Fig. 24).
Fig. 22 Blower Motor Resistor Block
1 ± RESISTOR BLOCK
2 ± ELECTRICAL CONNECTOR
Fig. 23 A/C Compressor Lines
1 ± CONDENSER LIQUID LINE
2 ± SUCTION LINE
3 ± COMPRESSOR MANIFOLD SCREWS
4 ± COMPRESSOR
5 ± DISCHARGE LINE
24 - 22 HEATING AND AIR CONDITIONINGPL
REMOVAL AND INSTALLATION (Continued)

(8) Remove compressor. If refrigerant lines were
not removed, lift compressor/clutch assembly and tie
it to a suitable component.
INSTALLATION
For installation, reverse the above procedures.
²Tighten the compressor mounting bolts to 28
N´m (250 in lbs).
²Tighten the compressor lines to 12 N´m (108 in
lbs).
COMPRESSOR CLUTCH/COIL ASSEMBLY
Compressor assembly must be removed from
mounting. Although, refrigerant discharge is not nec-
essary.
REMOVAL
(1) Remove the compressor shaft bolt (Fig. 25). A
band type oil filter removal tool can be placed around
the clutch plate to aid in bolt removal.
(2) Tap the clutch plate with a plastic hammer and
remove clutch plate and shim(s) (Fig. 26).
NOTE: Use care not to lose any of the shim(s).CAUTION: Do not use screwdrivers between the
clutch plate assembly and pulley to remove front
plate as this may damage the front plate assembly.
Fig. 24 A/C Compressor Mounting Bolts
1 ± A/C COMPRESSOR
2 ± MOUNTING BOLTS
3 ± LOWER FRONT STRUT-TO-ENGINE BRACKET
Fig. 25 Compressor Shaft Bolt and Clutch Plate
1 ± COMPRESSOR SHAFT BOLT
2 ± COMPRESSOR CLUTCH PLATE
Fig. 26 Clutch Plate and Shim(s)
1 ± COMPRESSOR SHAFT
2 ± CLUTCH PLATE
3 ± CLUTCH PLATE SHIM
PLHEATING AND AIR CONDITIONING 24 - 23
REMOVAL AND INSTALLATION (Continued)

obtained, add or subtract shims until desired read-
ing is obtained.
(8) Install compressor shaft bolt. Tighten to 17.56
2 N´m (155620 in. lbs.) torque.
NOTE: Shims may compress after tightening shaft
nut. Check air gap in four or more places to verify if
air gap is still correct. Spin pulley for final check.
CLUTCH BREAK-IN
After new clutch installation, cycle the A/C clutch
20 times (5 seconds on and 5 seconds off). During
this procedure, set the system to the A/C mode,
engine rpm at 1500 - 2000, and high blower speed.
This procedure (burnishing) will seat the opposing
friction surfaces and provide a higher clutch torque
capability.
CONDENSATION DRAIN TUBE
REMOVAL
(1) Raise vehicle.
(2) Locate rubber drain tube on right side of dash
panel (Fig. 30).
(3) Squeeze clamp and remove drain tube.
INSTALLATION
To install, reverse the preceding operation. Check
the drain tube nipple on the heater-A/C housing for
any obstructions.
CONDENSER
The condenser is located in front of the engine
radiator. It has no serviceable parts. If damaged or
leaking, the condenser assembly must be replaced.
WARNING: THE REFRIGERANT MUST BE
REMOVED FROM THE SYSTEM BEFORE REMOV-
ING THE CONDENSER.
REMOVAL
(1) Using a R-134a refrigerant recovery machine,
remove the refrigerant from the A/C system.
(2) Remove battery support strut.
(3) Remove refrigerant lines from condenser (Fig.
31).
(4) Remove upper radiator mounts.
(5) Remove condenser to radiator mounting
screws.
(6) Tilt radiator back and remove condenser.
INSTALLATION
For installation, reverse the above procedures.
²Tighten the condenser refrigerant lines to 5 N´m
(45 in lbs).
Fig. 29 Installing Pulley Assembly
1 ± PULLEY ASSEMBLY
2 ± WOOD BLOCK
Fig. 30 Condensate Water Drain Tube ± Typical
1 ± DASH PANEL (UNDER HOOD RIGHT SIDE)
2 ± CLAMP
3 ± CONDENSATE DRAIN TUBE
4 ± NIPPLE-A/C HEATER HOUSING
PLHEATING AND AIR CONDITIONING 24 - 25
REMOVAL AND INSTALLATION (Continued)

REMOVAL
(1) Remove the wire connector from the low pres-
sure cut-off switch.
(2) Remove the center bolt of refrigerant line
plumbing sealing plate (Fig. 37).
(3) Carefully pull the refrigerant line-sealing plate
assembly from the expansion valve towards front of
vehicle. Do not scratch the expansion valve sealing
surfaces with pilot tubes.
(4) Cover the openings on A/C line-sealing plate
assembly to prevent contamination.
(5) Remove two screws securing the expansion
valve to the evaporator sealing plate.
(6) Carefully remove valve.
INSTALLATION
(1) Remove and replace the aluminum gasket on
the evaporator sealing plate.
(2) Carefully hold the expansion valve to the evap-
orator sealing plate so not to scratch the sealing sur-
face. Install two screws and tighten to 1163 N´m
(100630 in. lbs.).
(3) Remove and replace the aluminum gasket on
the refrigerant line- sealing plate assembly.
(4) Carefully hold the refrigerant line-sealing plate
assembly to the expansion valve. Install bolt and
tighten to 2363 N´m (200630 in. lbs.).
(5) Connect wires to low pressure cut-off switch.
(6) Evacuate and recharge system.
(7) After expansion valve is installed, system is
charged, and leaks have been checked, repeat A/C
performance check.
HEATER CORE
Refer to HVAC Housing Disassembly and Assembly
in this section for heater core removal procedure.
HEATER HOSES
CAUTION: When removing hoses from heater core
inlet or outlet nipples DO NOT exert excess pres-
sure. The heater core may become damaged and
leak engine coolant.
NOTE: Review Cooling System Precautions before
proceeding with this operation.
REMOVAL
(1) Drain engine cooling system. Refer to Group 7,
Cooling System.
(2) Using spring tension clamp pliers, remove
clamps at end of heater hose to be removed (Fig. 38).
(3) Carefully rotate hose back and forth while pull-
ing away from connector nipple.INSTALLATION
For installation, reverse the above procedures.
Fig. 37 Expansion Valve - Typical
1 ± ALUMINUM N-GASKET
2 ± PLUMBING SEALING PLATE
3 ± LOW/DIFFERENTIAL PRESSURE CUT-OFF SWITCH
4 ± DASH PANEL
5 ± H-VALVE
6 ± EVAPORATOR SEALING PLATE
7 ± H-VALVE
Fig. 38 Heater Hoses and Clamps
1 ± COWL PANEL
2 ± HEATER HOSE AND CLAMPS
3 ± HEATER CORE TUBES
4 ± HEATER HOSE SUPPLY AND RETURN TUBES
24 - 28 HEATING AND AIR CONDITIONINGPL
REMOVAL AND INSTALLATION (Continued)

(6) Remove expansion valve from evaporator, and
cap fittings.
(7) Remove rubber drain tube extension from con-
densation drain tube.
(8) Disconnect the vacuum harness at the power
brake booster (Fig. 48).
(9) Unsnap and remove the defroster duct (Fig.
49).(10) Remove three retaining nuts located in the
engine compartment, on the dash panel (Fig. 50).
(11) Remove the right side retaining screw (Fig.
51).
(12) Remove remaining nut located on dash panel
stud.
(13) Disconnect the wiring connectors.
(14) Remove assembly from the vehicle.
Fig. 48 HVAC Vacuum Harness
1 ± BRAKE POWER BOOSTER
2 ± A/C VACUUM CHECK VALVE
3 ± VACUUM HARNESS
Fig. 49 HVAC Housing Defroster Duct
1 ± DEFROSTER DUCT
2 ± BODY
3 ± ELECTRICAL CONNECTOR
4 ± HVAC HOUSING
Fig. 50 Dash Panel Retaining Studs
1 ± BLOWER RESISTOR
2 ± EXPANSION VALVE
3 ± DRAIN TUBE
4 ± DASH PANEL
5 ± HEATER HOSES
6 ± RETAINING STUDS
Fig. 51 Housing Screws
1 ± RIGHT SIDE RETAINING SCREW
2 ± EVAPORATOR PROBE GROMMET
3 ± SCREW BOSSES
4 ± DASH PANEL STUD AND NUT
PLHEATING AND AIR CONDITIONING 24 - 33
REMOVAL AND INSTALLATION (Continued)