1999 DODGE RAM heater

Fig. 2: Identifying Compressor Clutch Relay Terminals (Typical)
Courtesy of Chrysler Corp.
BLOWER MOTOR RESISTOR
1) Disconnect negative battery cable. Disconnect blower motor
resistor harness connector. Using an ohmmeter, check for continuity
between all 4 front blower motor resistor terminals, or 3 rear blower
motor resistor terminals. If continuity exists, go to next step. If
continuity does not exist, replace faulty blower motor resistor.
2) Check for open or short in circuits between blower motor
resistor and A/C-heater control panel. Also check for open or short in
wire between blower motor resistor and blower motor.
BLOWER MOTOR SWITCH
Front
1) Using a voltmeter, check underhood power distribution
center for battery voltage at fuse No. 5 (40-amp) on Dakota and
Durango, or fuse No. 5 (40-amp) on Ram Pickup. If battery voltage
exists, go to next step. If battery voltage does not exist, check for
open in Red wire between battery and underhood power distribution
center. If Red wire is okay, replace underhood power distribution
center.
2) Disconnect negative battery cable. Remove A/C-heater
control panel. See A/C-HEATER CONTROL PANEL R & I . Disconnect A/C-
heater control panel harness connector. Using an ohmmeter, check for
continuity between A/C-heater control panel harness connector terminal
No. 7 (Black wire on Dakota and Durango; Black/Orange on Ram Pickup)
and ground. If continuity exists, go to step 4).
3) If continuity does not exist, repair open in Black or
Black/Orange wire between A/C-heater control panel harness connector
terminal No. 7 and ground connector located at lower right corner of
instrument panel (Dakota and Durango) or behind center of instrument
panel (Ram Pickup).
4) Place mode control knob to any position except OFF. Using
an ohmmeter, check for continuity between A/C-heater control panel
connector terminal No. 7 and terminals No. 3, 4, 5, and 6 while
rotating blower motor switch. See Fig. 3.
5) If continuity does not exist at any terminal, replace
faulty A/C-heater control panel. If continuity exists as specified,
check for open in circuits between A/C-heater control panel and blower
motor resistor. Also check for an open in circuit between A/C-heater

control panel and blower motor.
Fig. 3: Identifying Blower Motor Switch Connector Terminals (Typical)\
Courtesy of Chrysler Corp.
Rear (Durango)
1) Disconnect negative battery cable. Remove rear blower
motor switch located in headliner. See BLOWER MOTOR SWITCH (REAR)
under REMOVAL & INSTALLATION. Disconnect rear blower motor switch
connector. Using an ohmmeter, check continuity between rear blower
motor switch connector Black wire and ground. If continuity exists, go
to next step. If continuity does not exist, repair open in Black wire
between rear blower motor switch connector and ground connector
located at left rear of vehicle body.
2) Place blower motor switch knob to any position except OFF.
Using an ohmmeter, check for continuity between rear blower motor
switch connector Black wire and Black/Light Blue wire, and
Black/Orange wire and Dark Green wire while rotating blower motor
switch.
3) If continuity does not exist at any terminal, replace
faulty blower motor switch. If continuity exists as specified, check
for open in circuits between blower motor switch and blower motor
resistor. Also check for an open in circuit between blower motor
switch connector and blower motor relay.
CLUTCH CYCLING PRESSURE SWITCH
Dakota & Ram Pickup
1) Locate clutch cycling pressure switch on side or top of
A/C accumulator. Ensure clutch cycling pressure switch is properly
installed on A/C accumulator fitting. Ensure system pressure is
correct. See A/C SYSTEM PERFORMANCE test.
2) Start and run engine with A/C on. If clutch cycles, turn
engine off and disconnect negative battery cable. Disconnect clutch
cycling pressure switch connector. Place a jumper wire across
terminals of clutch cycling pressure switch harness connector. Connect
negative battery cable. Connect manifold gauge set. Set A/C-heater

1) Locate low pressure cut-out switch located on suction
line, near firewall. Ensure system pressure is correct. See
A/C SYSTEM PERFORMANCE test. Disconnect negative battery cable.
Disconnect low pressure cut-out switch connector.
2) Place a jumper wire across terminals of low pressure cut-
out switch harness connector. Connect negative battery cable. Connect
manifold gauge set. Set A/C-heater controls to A/C. Start and operate
engine at idle speed.
3) Using an ohmmeter, check for continuity between switch
terminals. Continuity should exist when suction pressure reading is
between 13-27 psi (.9-1.9 kg/cm
). Continuity should not exist when
suction pressure reading is 10 psi (.7 kg/cm) or lower. If switch is
okay, repair open or short in Brown wire between low pressure cut-out
switch and PCM. If switch is not okay, replace faulty low pressure
cut-out switch.
REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY
article.
A/C-HEATER ASSEMBLY
Removal (Dakota & Durango - Front)
1) Disconnect negative battery cable. Drain cooling system.
Discharge A/C system, using approved refrigerant recovery/recycling
equipment. Disconnect refrigerant lines from evaporator and plug or
cover all openings in A/C system. Remove instrument panel. See
INSTRUMENT PANEL .
2) In engine compartment, disconnect heater hoses. Remove 4
A/C-heater assembly nuts from engine compartment firewall. Inside
vehicle, remove A/C-heater assembly support brace screw, and swing
support brace out of way. Move passenger seat rearward.
3) Carefully pull A/C-heater assembly rearward until studs
and heater core tubes clear firewall. Lower A/C-heater assembly and
rotate assembly until studs are facing downward. Remove A/C-heater
assembly from vehicle. See Fig. 4.
4) Place A/C-heater assembly on work bench with assembly
housing cover facing down. Remove 2 screws securing A/C-heater
assembly housing cover to blower motor housing cover. Unplug vacuum
harness connector from panel/defrost door actuator.
5) Remove floor duct from A/C-heater assembly housing. Remove
2 screws securing A/C-heater assembly housing cover to lower housing
near floor outlet. Turn assembly over. Disengage vacuum harness
retainer and vacuum harness. Remove 13 screws securing housing cover.
6) Remove blend-air door lever. Gently pry panel-defrost door
lever off. Pull up on A/C-heater assembly housing cover far enough to
separate cover sealant and remove cover.
Installation
Ensure blower motor housing cover sealant is in place and in
good condition. To complete installation, reverse removal procedure.

Fig. 4: A/C-Heater Housing Removal/Installation (Dakota & Durango -
Front)
Courtesy of Chrysler Corp.

Fig. 5: Exploded View Of A/C-Heater Assembly (Ram Pickup)
Courtesy of Chrysler Corp.
Removal & Installation (Durango - Rear)
1) Disconnect negative battery cable. Discharge A/C system,
using approved refrigerant recovery/recycling equipment. Remove
headliner from passenger compartment of vehicle. Remove sun visors and
sun visor arm supports.
2) Remove coat hooks, overhead assist handle and dome light.
If equipped, remove overhead console. Remove air outlet bezel from
rear A/C-heater assembly. Remove rear blower motor switch. Remove
upper liftgate opening trim. Disengage "A", "B", "C", and "D" pillar
trim as necessary to prevent trim panel interference.
3) Move second and third row seats to cargo position. Move
front seats to full recline position. Remove headliner fasteners.
Carefully bow headliner and remove through lift gate opening.
4) Disconnect "B" pillar drain hoses from "Y" fittings.
Disconnect "B" pillar refrigerant lines and plug or cover all openings
in A/C system. Disconnect rear A/C-heater assembly harness connector.
Loosen but DO NOT remove screws securing left end of rear A/C-heater
assembly. Support right end of rear A/C-heater assembly. Remove screws
from right side of rear A/C-heater assembly. Slide rear A/C-heater

assembly towards right side of vehicle and remove rear A/C-heater
assembly.
5) To install, reverse removal procedure. Ensure all wiring
and hoses are clear and not pinched. Tighten bolts and nuts to
specification. See TORQUE SPECIFICATIONS .
Removal (Ram Pickup - Front)
1) Disconnect negative battery cable. Drain cooling system.
In engine compartment, remove coolant hoses from heater core tubes.
Remove coolant overflow bottle.
2) Discharge A/C system, using approved refrigerant
recovery/recycling equipment. Disconnect refrigerant lines from
evaporator and plug or cover all openings in A/C system. Remove
instrument panel. See INSTRUMENT PANEL. Remove Powertrain Control
Module (PCM) and position aside. DO NOT disconnect 60-pin connector
from PCM.
3) Remove attaching nuts from studs on engine compartment
side of dash panel. Remove defrost duct. Disconnect electrical
connectors. Remove attaching nuts from studs in passenger compartment
side of dash panel. Remove A/C-heater assembly from vehicle. See
Fig. 5 .
4) Place A/C-heater assembly upside-down on work bench.
Remove screw securing floor duct to bottom of A/C-heater assembly and
slide floor duct off of center heat duct adapter. Unsnap center heat
duct adapter from bottom of A/C-heater assembly housing. Remove screw
hidden behind adapter. Remove remaining screws and separate A/C-heater
assembly.
Installation
Ensure mode door pivot pins are properly inserted in holes.
To complete installation, reverse removal procedure.
A/C-HEATER CONTROL PANEL R & I
Removal & Installation (Dakota & Durango)
1) Disconnect negative battery cable. On models equipped with
A/T, unlock ignition switch. Set parking brake and place gear selector
lever in "L" position. If equipped, set tilt steering column in lowest
position.
2) On all models, carefully pry bezel away from instrument
panel to disengage clips. Unplug connectors from cigarette lighter and
auxiliary power outlet. Disconnect fog light switch (if equipped).
Remove A/C-heater control panel screws.
3) Pull control panel outward enough to disconnect wiring
connector, vacuum harness, and temperature control cable. Remove A/C-
heater control panel. To install, reverse removal procedure. Adjust
temperature control cable. See TEMPERATURE CONTROL CABLE ADJUSTMENT .
Removal & Installation (Ram Pickup)
1) Disconnect negative battery cable. Reach under driver's
side of instrument panel, near transmission tunnel and unplug A/C-
heater control panel to A/C-heater assembly vacuum harness connector.
Disconnect vacuum harness from center air duct.
2) On models equipped with A/T, unlock ignition switch. Set
parking brake and place gear selector lever in "L" position. If
equipped, set tilt steering column in lowest position.
3) On all models, remove screw securing cluster bezel to
instrument panel. See Fig. 6. Carefully pry bezel away from instrument
panel to disengage clips. Unplug connectors from cigarette lighter and
auxiliary power outlet.
4) Remove 4 screws attaching A/C-heater control panel. Pull
control panel outward enough to disconnect wiring connector, vacuum
harness and temperature control cable. Remove A/C-heater control

panel. To install, reverse removal procedure.
Fig. 6: Removing Cluster Bezel (Ram Pickup)
Courtesy of Chrysler Corp.
ACCUMULATOR
Removal & Installation
1) Disconnect negative battery cable. Discharge A/C system,
using approved refrigerant recovery/recycling equipment. Disconnect
clutch cycling pressure switch connector.
2) On Dakota, remove nuts securing cruise control servo
mounting bracket to studs on cowl plenum panel (if equipped). Move
servo far enough to access accumulator refrigerant lines.
3) On all models, disconnect refrigerant lines from A/C
compressor and evaporator. Plug or cover all openings in A/C system.
Loosen support bracket screw. Remove accumulator.
4) To install, reverse removal procedure. Install new "O"
rings. Evacuate and charge A/C system.
BLOWER MOTOR
Removal (Dakota & Durango - Front)
1) Disconnect negative battery cable. Remove and disassemble
A/C-heater assembly. See A/C-HEATER ASSEMBLY. Disconnect blower motor
lead at bottom of housing. Remove 6 screws and blower motor housing
cover.
2) Remove 3 screws and blower motor and fan assembly. Place
reference marks on blower motor and fan for reassembly reference.
Remove blower fan retainer clip. Pull blower motor fan off blower
motor shaft.
Installation
Align reference marks. Press blower fan hub onto blower motor
shaft. Ensure retainer clip ears are indexed over flats of blower
motor shaft and fan hub. To complete installation, reverse removal

procedure.
NOTE: On Durango rear A/C-heater assembly, blower motor and fan are
serviced as an assembly.
Removal (Durango - Rear)
1) Disconnect negative battery cable. Remove headliner from
passenger compartment of vehicle. Remove sun visors and sun visor arm
supports.
2) Remove coat hooks, overhead assist handle and dome light.
If equipped, remove overhead console. Remove air outlet bezel from
rear A/C-assembly. Remove rear blower motor switch. Remove upper
liftgate opening trim. Disengage "A", "B", "C", and "D" pillar trim as
necessary to prevent trim panel interference.
3) Move second and third row seats to cargo position. Move
front seats to full recline position. Remove headliner fasteners.
Carefully bow headliner and remove through lift gate opening.
4) Disconnect "B" pillar drain hoses from "Y" fittings.
Remove lower A/C-heater assembly cover. Disconnect blower motor
harness connector. Remove blower motor and fan assembly. To install,
reverse removal procedure.
Removal (Ram Pickup - Front)
1) Disconnect negative battery cable. Disconnect blower motor
cooling tube. Remove blower motor electrical connector from retainer.
Disconnect electrical connector. See Fig. 5.
2) Remove blower motor and fan assembly mounting screws.
Remove blower motor and fan assembly. Place reference marks on blower
motor and fan for reassembly reference. Remove blower motor fan
retainer clip. Pull blower motor fan off blower motor shaft.
Installation
Align reference marks made during removal. Press blower fan
hub onto blower motor shaft. Ensure retainer clip ears are indexed
over flats of blower motor shaft and fan hub. Ensure blower motor seal
is installed on housing. To complete installation, reverse removal
procedure.
BLOWER MOTOR RESISTOR
Removal & Installation (Dakota & Durango - Front)
Blower motor resistor is located in engine compartment, under
upper right corner of dash panel. Disconnect negative battery cable.
Remove cowl plenum cover to access resistor. Remove blower motor
resistor connector. Remove resistor retaining screws. Remove blower
motor resistor. To install, reverse removal procedure.
Removal & Installation (Durango - Rear)
1) Rear blower motor resistor is located in A/C-heater
assembly. Disconnect negative battery cable. Remove headliner from
passenger compartment of vehicle. Remove sun visors and sun visor arm
supports.
2) Remove coat hooks, overhead assist handle and dome light.
If equipped, remove overhead console. Remove air outlet bezel from
rear A/C-assembly. Remove rear blower motor switch. Remove upper
liftgate opening trim. Disengage "A", "B", "C", and "D" pillar trim as
necessary to prevent trim panel interference.
3) Move second and third row seats to cargo position. Move
front seats to full recline position. Remove headliner fasteners.
Carefully bow headliner and remove through lift gate opening.
4) Disconnect "B" pillar drain hoses from "Y" fittings.
Remove lower A/C-heater assembly cover. Disconnect rear blower motor
resistor connector. Remove screw and rear blower motor resistor. To