1999 DODGE RAM Service Repair Manual

5) Once compressor shaft nut is tightened, check air gap
between clutch plate and pulley surface in at least 4 places. Readjust
air gap if necessary. Install A/C compressor. Evacuate and charge
system. Perform leak test. Ensure A/C system is operating properly.
6) After completing compressor clutch installation, start
engine. Set A/C-heater control to recirculated air mode and high
blower motor speed. Set engine speed to 1500-2000 RPM. Cycle
compressor on for 5 seconds and off for 5 seconds, about 20 times to
break-in clutch.
SHAFT SEAL
Shaft seal is not serviceable. If excessive oil is present on
pulley and plate friction surfaces or on compressor shaft nose area,
replace compressor.
ZEXEL ROTARY VANE
CLUTCH ASSEMBLY
NOTE: Discharging A/C system and removing refrigerant lines from
compressor is not necessary to service clutch assembly.
Removal
1) Loosen tensioner and remove drive belt from pulley.
Disconnect clutch electrical connector. Remove compressor mounting
bolts. With refrigerant lines connected lift compressor upward and
forward. Install one front mounting bolt through bottom rear
compressor mounting ear. Tighten bolt so compressor is supported by
mounting bracket.
2) Using Clutch Drive Plate Holder (SA9510AC), remove clutch\
drive plate center bolt. Insert Clutch Drive Plate Remover Sleeve
(SA9506AC) into center of drive plate. Install remover bolt. While
holding clutch remover sleeve, tighten remover bolt and remove drive
plate and shims.
3) Remove pulley external snap ring. Position Puller Center
Adapter (SA9149AC-2) over end of compressor shaft. Attach 3-jaw puller\
to back of pulley. Tighten puller bolt against pulley center adapter
and remove pulley. Remove clutch coil screws. Disconnect clutch coil
wire. Remove clutch coil.
Installation
1) Install coil in original position. Ensure electrical
connector is aligned with indent in front of compressor head. Tighten
screws to 44 INCH lbs. (5 N.m). Place Drive Plate Installer (SA9149AC\
-
3) and thrust bearing on installation bolt and insert through center
of pulley. Finger-tighten pulley installation bolt into compressor
shaft.
2) Finger-tighten nut on installation bolt to align pulley to
compressor. Hold end of bolt and tighten nut until pulley bottoms on
compressor. Loosen nut and remove installation bolt, thrust bearing
and drive plate installer. Install snap ring with tapered side out.
3) Install thrust bearing on installation bolt and insert
through clutch drive plate. Place original shims on installation bolt.
Thread bolt into compressor shaft. Hold end of bolt and tighten nut
until clutch drive plate bottoms out. Loosen nut and remove
installation bolt and thrust bearing. Install center bolt and tighten
to 115 INCH lbs. (13 N.m) using clutch drive plate holder.
4) Using a feeler gauge, measure air gap between drive plate
and pulley. Air gap should be 0.018-0.030" (0.46-0.76 mm). If air gap
is not as specified, add or remove shims as necessary. Install
compressor onto mounting bracket. Tighten front bolts to 36 ft. lbs.


A/C -H EA TE R S YSTE M T R O UBLE S H O OTIN G

1999 D odge P ic ku p R 1500
1999 MANUAL A/C-HEATER SYSTEMS
Trouble Shooting - Cars & Trucks
CHRYSLER
Avenger, Breeze, Caravan, Cirrus, Concorde, Dakota, Durango,
Intrepid, LHS, Neon, Ram Pickup, Ram Van/Wagon, Sebring Convertible,
Sebring Coupe, Stratus, Town & Country, Voyager, 300M
A/C SYSTEM DIAGNOSIS
RAPID COMPRESSOR CLUTCH CYCLING
Some possible causes of rapid compressor clutch cycling,
clutch cycles 10 or more times per minute, include:
* Low refrigerant system charge.
* Faulty low pressure cycling clutch switch.
* Faulty PCM.
COMPRESSOR WILL NOT ENGAGE
Some possible causes of compressor not engaging with high and
low side system pressures equal include:
* No refrigerant in system.
* Faulty fuse.
* Faulty compressor clutch coil.
* Faulty compressor clutch relay.
* Faulty electronic cycling clutch switch.
* Improperly installed or faulty low pressure cycling clutch
switch.
* Faulty low pressure cut-off switch.
* Faulty high pressure cut-off switch.
* Faulty PCM.
* Faulty A/C-heater control panel.
TEMPERATURE IS TOO HIGH WITH A/C ON
Some possible causes of high temperature output at center
panel when A/C system pressure is normal include:
* Excessive oil charge in refrigerant.
* Temperature control cable improperly installed or faulty.
* Blend-air door inoperative, obstructed or sealing
improperly.
* Blend door actuator not calibrated.
LOW SIDE PRESSURE IS LOW-TO-NORMAL & HIGH SIDE PRESSURE IS
LOW
Some possible causes of low side system pressure being lower-
to-normal and high side system pressure being too low include:
* Low refrigerant system charge.
* Refrigerant flow through accumulator is restricted.
* Refrigerant flow through evaporator is restricted.
* Faulty compressor.
LOW SIDE PRESSURE IS HIGH-TO-NORMAL & HIGH SIDE PRESSURE IS

HIGH
Some possible causes of low side system pressure being high-
to-normal and high side system pressure being too high include:
* Condenser air flow restricted.
* Inoperative cooling fan.
* Faulty expansion valve.
* Refrigerant system overcharged.
* Air in refrigerant system.
* Engine overheating.
LOW SIDE PRESSURE IS HIGH & HIGH SIDE PRESSURE IS LOW
Some possible causes of low side system pressure being too
high and high side system pressure being too low include:
* Compressor belt is slipping.
* Fixed orifice tube not installed.
* Faulty compressor.
LOW SIDE PRESSURE IS LOW & HIGH SIDE PRESSURE IS HIGH
Some possible causes of low side system pressure being too
low and high side system pressure being too high include:
* Restricted refrigerant flow through refrigerant lines.
* Restricted refrigerant flow through expansion valve.
* Restricted refrigerant flow through fixed orifice tube.
* Restricted refrigerant flow through receiver-drier.
* Restricted refrigerant flow through condenser.
BLOWER MOTOR DIAGNOSIS
BLOWER MOTOR INOPERATIVE
Some possible causes of an inoperative blower motor include:
* Faulty fuse.
* Faulty blower motor feed circuit wire harness or
connectors.
* Faulty blower motor ground circuit wire harness or
connector.
* Faulty blower motor resistor.
* Faulty blower motor relay.
* Faulty blower motor switch.
* Faulty A/C-heater mode control switch.
* Faulty blower motor.
BLOWER NOT OPERATING IN ALL SPEEDS
Possible causes of the blower not operating in all speeds
include:
* Faulty fuse.
* Faulty blower motor feed circuit wire harness or
connectors.
* Faulty blower motor relay.
* Faulty blower motor resistor.
* Faulty blower motor switch.

BLOWER MOTOR VIBRATION
Possible causes of blower motor vibration include:
* Improper blower motor mounting.
* Improper blower wheel or fan mounting.
* Blower wheel or fan out of balance.
* Blower motor faulty.
BLOWER MOTOR NOISE
Possible causes of blower motor noise include:
* Foreign material in blower motor housing.
* Foreign material in A/C-heater housing.
* Improper blower motor mounting.
* Improper blower wheel or fan mounting.
* Blower motor faulty.
VACUUM CONTROL SYSTEM DIAGNOSIS
VACUUM CONTROL ONE-WAY CHECK VALVE
NOTE: Some models use brake booster check valve for vacuum source.
These models do not use another in-line vacuum check valve.
1) In engine compartment, locate Black vacuum hose that runs
from brake booster check valve or intake manifold, through firewall
near heater hoses or expansion valve. This supply vacuum hose goes to
A/C-heater control panel vacuum switch.
2) Within Black vacuum hose, disconnect and remove check
valve near intake manifold or brake booster. Connect vacuum gauge to
an external vacuum pump. Start vacuum pump. Plug end of hose probe on
vacuum gauge. Adjust bleed valve on vacuum gauge to obtain an exact
vacuum reading of 8 in. Hg.
3) Unplug and plug end of hose probe on vacuum gauge several
times to ensure exact vacuum reading. Connect vacuum gauge hose probe
to control panel side of check valve. Vacuum gauge reading should be 8
in. Hg. Replace check valve if vacuum leak exists.
4) Connect vacuum gauge hose probe to engine side of check
valve. Vacuum should flow through check valve. Replace check valve if
operation is not as described.
VACUUM CONTROLS
1) This test checks for proper function of control panel
vacuum circuits. Perform steps 1) through 4) under VACUUM CONTROL ONE-\
WAY CHECK VALVE.
2) Connect vacuum gauge hose probe to Black vacuum hose end
that leads to A/C-heater control panel switch. Position vacuum gauge
so gauge reading can be observed from inside vehicle.
3) Operate A/C-heater controls (sliding lever or push
buttons) in all mode positions (floor, defrost, panel, etc.). Pause
after each selection to allow vacuum actuators or motors to energize
and stabilize. Record vacuum gauge reading at each selection.
4) After each selection, vacuum reading should be 7.5-8 in.
Hg. Maximum vacuum reading drop is .75 in. Hg. If proper vacuum
reading cannot be obtained, vacuum leak exists in selected circuit.
5) To check for vacuum leak(s), disconnect 7-way A/C-heater
control panel vacuum harness connector. See Fig. 1. If necessary,
remove control panel from instrument panel to access A/C-heater
control panel vacuum harness connector, or remove lower instrument

panel assembly.
6) Connect vacuum source probe to each port of connector. See
Fig. 1. Record each vacuum gauge reading. Vacuum reading should be 8
in. Hg at each port.
NOTE: Brown (bi-level) vacuum circuit contains a restriction in
line. It takes longer to obtain correct vacuum reading on
this line.
7) If correct vacuum readings are obtained, replace faulty
A/C-heater control panel vacuum switch assembly. If proper vacuum
readings are not obtained, check appropriate vacuum circuit.
8) Start vacuum check by plugging vacuum hose at vacuum
actuator in suspect circuit. Recheck vacuum circuit by connecting
vacuum source probe to proper port.
9) If proper vacuum reading is now obtained, replace vacuum
actuator. If proper reading is not obtained, check vacuum hoses and
connections for leak. Repair or replace as required.
Fig. 1: Testing A/C-Heater System Vacuum Control Circuits
Courtesy of Chrysler Corp.
TROUBLE SHOOTING

Fig. 2: Blower Motor System Diagnosis (Except RWD Van)
Courtesy of Chrysler Corp.

Fig. 3: Blower Motor & Control System Diagnosis (RWD Van)
Courtesy of Chrysler Corp.

Fig. 4: Blower Motor Noise & Vibration Diagnosis
Courtesy of Chrysler Corp.