1999 DODGE RAM light

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

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

from housing. To install, reverse removal procedure. Install new "O"
rings to A/C fittings. Evacuate and charge A/C system.
Removal & Installation (Durango - Rear Evaporator Core)
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. Remove lower A/C-heater assembly cover. Remove screws
securing refrigerant tube and retaining strap to right side of upper
housing cover. Remove evaporator core. To install, reverse removal
procedure. Install new "O" rings to A/C fittings. Evacuate and charge
A/C system.
Removal & Installation (Ram Pickup - Front)
1) Remove and disassemble A/C-heater housing. See
A/C-HEATER ASSEMBLY . Separate halves of A/C-heater housing and remove
top half. Remove evaporator or heater core from housing.
2) To install, reverse removal procedure. Install new "O"
rings to A/C fittings. Evacuate and charge A/C system. Fill cooling
system. On 5.9L diesel engine, engine is equipped with a one-way check
valve. DO NOT run engine while filling cooling system. Fill engine
with engine turned off.
INSTRUMENT PANEL
Removal & Installation (Dakota & Durango)
1) Disconnect negative battery cable. Disable air bag system.
See AIR BAG SYSTEM SAFETY article. Place front wheels in straight-
ahead position. Remove sill trim from both doorways. Remove kick panel
covers from both sides of vehicle. Remove mounting screws for hood
release handle.
2) Remove steering column trim panel and support bracket.
Remove tilt steering column lever (if equipped). Remove upper and
lower shrouds from steering column. Unplug driver's side air bag
module. Loosen multifunction switch wiring harness connector screw and
disconnect from switch. Screw will remain in connector.
3) Disconnect PRNDL cable. Disconnect shift cable from
steering column. Remove steering coupler lock pin. Remove toe plate
retaining screws. Remove steering column mounting bolts and remove
steering column from vehicle.
4) Remove screw from bulkhead wiring harness connector and
disconnect. Disconnect 2 body wiring harness connectors located next
to bulkhead connector. Disconnect 3 wiring harness connectors, from
junction block, located nearest to dash panel. Disconnect brake light
switch connector. Disconnect Rear Wheel Anti-Lock (RWAL) brake module
(if equipped), located near steering column support brackets.
5) Disconnect plastic retainer clip from parking brake
linkage rod, located at back of parking brake release handle. Remove
rod end from parking brake handle. Remove instrument panel center
support bracket. Unplug vacuum harness connector located at left end
of A/C-heater housing. Disconnect Air Bag Control Module (ACM)
connector.

6) Remove glove box. Reach through glove box opening and
disconnect antenna coaxial cable connector. Disconnect blower motor
connector located above glove box opening, near support brace for A/C-
heater housing. Disconnect radio ground strap. Loosen instrument panel
roll down bracket bolts about 2 turns, located at lower corners on
both sides of instrument panel. Remove 5 screws across top of dash
panel at base of windshield, removing center screw last.
7) Roll down instrument panel and install a temporary support
hook that is about 18" (457 mm) in length. Install hook from center
hole in instrument panel to center hole of dash panel. Pull lower
instrument panel outward until both roll down bracket bolts are in
slotted roll down position. Instrument panel should now be supported
and away from firewall.
8) Disconnect 2 door harness connectors, located on a bracket
near right end of instrument panel. Disconnect blower motor resistor.
Disconnect temperature control cable from A/C-heater housing and
remove from housing. See Fig. 5. Disconnect demister duct flexible
hose from A/C-heater housing.
9) Ensure instrument panel is free and clear for removal.
With the aid of an assistant, remove temporary support hook. Lift
instrument panel off of roll down bracket bolts and remove from
vehicle.
10) To install, reverse removal procedure. Ensure all wiring
and hoses are clear and not pinched. Tighten bolts and nuts to
specification. See TORQUE SPECIFICATIONS . Enable air bag system. See
AIR BAG SYSTEM SAFETY article.
Removal & Installation (Ram Pickup)
1) Disable air bag system. See AIR BAG SYSTEM SAFETY article.
Disconnect negative battery cable. Drain cooling system. Remove left
and right kick panel trim. Remove 5 screws and knee bolster/steering
column cover. Remove hood release and parking brake release handle
screws from lower instrument panel support. Remove 6 screws and
instrument panel support. Disconnect air bag connector at lower left
corner of instrument panel.
2) Pull PRNDL cable and twist to remove from position arm.
Push tab on bottom of cable retainer upward, then squeeze sides to
remove retainer from column. Remove tilt lever (tilt column only).
Remove both upper and lower shrouds from column. Remove lower fixed
column shroud. Loosen multifunction switch connector screw. Screw will
remain in connector.
3) Remove remaining steering column electrical connectors.
Remove air bag wiring harness from steering column wiring trough.
Remove wiring trough from steering column. Remove 3 toe plate nuts and
washers.
4) Remove 2 nuts and washers attaching steering column
bracket to instrument panel steering column support bracket. Allow
column to lower and rest on seat. Remove 2 screws from bottom of Air
Bag Control Module (ACM) cover. Remove 4 screws holding ACM to
transmission tunnel.
5) Disconnect wiring at ACM. Disconnect instrument panel left
side wiring connectors. Remove screw holding brake release to bottom
of instrument panel. Disconnect instrument panel right side wiring
connectors, which includes 2 connectors attached to A/C-heater
assembly housing, courtesy light connector, antenna cable and 2 body
connectors. Disconnect vacuum harness from A/C-heater system.
6) Remove 5 screws holding instrument panel to dash. Loosen
lower instrument panel pivot bolts. Roll instrument panel downward.
Remove instrument panel from vehicle.
7) To install, reverse removal procedure. Ensure all wiring
and hoses are clear and not pinched. Tighten bolts and nuts to
specification. See TORQUE SPECIFICATIONS . Enable air bag system. See
AIR BAG SYSTEM SAFETY article.


A/C S YSTE M G EN ER AL S ER VIC IN G
1999 D odge P ic ku p R 1500
1999 GENERAL SERVICING
A/C System General Servicing
All Models
USING R-134a REFRIGERANT
HANDLING/SAFETY PRECAUTIONS
1) Always work in a well-ventilated, clean area. Refrigerant
is colorless and invisible as a gas. Refrigerant is heavier than
oxygen and will displace oxygen in a confined area. Avoid breathing
refrigerant vapors. Exposure may irritate eyes, nose and throat.
2) Always wear eye protection when working around A/C system
and refrigerant. The system's high pressure can cause severe injury to
eyes and skin if a hose were to burst. If necessary, wear rubber
gloves or other protective clothing.
3) Refrigerant evaporates quickly when exposed to atmosphere,
freezing anything it contacts. If liquid refrigerant contacts eyes or
skin (frostbite), DO NOT rub eyes or skin. Immediately flush affected
area with cool water for 15 minutes and consult a doctor or hospital.
4) Never use R-134a in combination with compressed air for
leak testing. Pressurized R-134a in the presence of oxygen (air
concentrations greater than 60 percent by volume) may form a
combustible mixture. DO NOT introduce compressed air into R-134a
containers (full or empty), A/C system components, or service
equipment.
5) DO NOT expose A/C system components to high temperatures
(steam cleaning for example), as excessive heat will cause refrigerant\
system pressure to increase. Never expose refrigerant directly to open
flame. If refrigerant needs to be warmed, place bottom of refrigerant
tank in warm water. Water temperature MUST NOT exceed 125
F (52C).
CAUTION: When R-134a is exposed to an open flame, drawn into engine,
or detected with a Halide (propane) leak tester, a poisonous
gas is formed. Keep work areas well ventilated.
6) Use care when handling refrigerant containers. DO NOT
drop, strike, puncture, or incinerate containers. Use DOT 4BW or DOT
4BA approved refrigerant containers.
7) Never overfill refrigerant containers. The safe filling
level of a refrigerant container MUST NOT exceed 60\% of the
container's gross weight rating. Store refrigerant containers at
temperatures less than 125
F (52C).
8) R-134a refrigerant is sold and stored in 30- or 50-pound
Light Blue containers, while Freon (R-12) is stored in White colored
containers.
9) Refrigerant R-12 and R-134a must never be mixed, as they
and their desiccants and lubricants are not compatible. If the
refrigerants are mixed, system cross-contamination or A/C system
component failure may occur. Always use separate servicing and
refrigerant recovery/recycling equipment.
10) Read and follow equipment manufacturer's instructions for
all service equipment to be used. The Material Safety Data Sheet
(MSDS), provided by refrigerant manufacturer/supplier, contains
valuable information regarding the safe handling of refrigerants.
IDENTIFYING R-134a SYSTEMS & COMPONENTS

Because R-134a is not interchangeable with R-12, separate
sets of hoses, gauges, and recovery/recycling equipment are required
to service vehicles. This is necessary to avoid cross-contamination
and damaging system.
All equipment used to service systems using R-134a must meet
SAE standard J2210. The service hoses on the manifold gauge set must
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.
For identification purposes, R-134a service hoses must have a
Black stripe along their length and be clearly labeled SAE J2196/134a.
The low pressure test hose is Blue with a Black stripe. The high-side
test hose is Red with a Black stripe. The center test hose is Yellow,
or White, with a Black stripe.
NOTE: Refrigerant R-12 service hoses will ONLY be labeled SAE
J2196.
All R-134a manifold gauge sets can be identified by one or
all of the following:
* Labeled FOR USE WITH R-134a on set.
* Labeled HFC-134 or R-134a on gauge face.
* Light Blue color on gauge face. In addition,
pressure/temperature scales on R-134a gauge sets are
different from R-12 manifold gauge sets.
MANIFOLD GAUGE SET
A manifold gauge set is used to determine the system's high-
side and low-side pressures, correct refrigerant charge, and operating
efficiency. High (discharge) and low (suction) pressures must be
compared to determine system operation. Manifold gauge sets for the 2
refrigerant types are basically the same except for fittings at ends
of hoses. Fittings are different to ensure connection only to
appropriate refrigerant system.
Low-Side Gauge
Low-side gauge, which may have a Blue identifying feature, is
used to measure low-side (suction) pressure. Low-side gauge is also
called a compound gauge because it can measure pressure and vacuum.
Pressure scale ranges from 0 to 150 psi; vacuum scale ranges from 0 to
30 in. Hg.
High-Side Gauge
High-side gauge, which may have a Red identifying feature, is
used to measure high-side (discharge) pressure. Gauge scale ranges
from 0 to 500 psi.
CONNECTING GAUGE SET
NOTE: R-134a quick disconnect service couplings are connected in
the same sequence as Schrader-type service valves.
Schrader-Type Valves
1) Put on safety goggles, and cover vehicle's fender. Slowly
remove protective caps from Schrader valves to check for leaky valves.
CAUTION: Ensure hand valves on manifold gauge set and the hose-end
shutoff valves are closed before attaching test hoses to
Schrader valves.

VALVES. Connect 2 hoses with shutoff valves to manifold gauge set
center port. Connect one hose to vacuum pump and other hose to
refrigerant container. Weight of refrigerant container before and
after charging can be used to determine amount of refrigerant drawn
into system. Using vacuum pump, purge air from center hoses.
3) Fully open manifold gauge set low-side valve and
refrigerant container valve to allow refrigerant to enter A/C system.
When no more refrigerant is being drawn into A/C system, start engine
and allow to idle. Select MAX A/C, set blower motor speed to maximum
and allow remaining refrigerant to be drawn into A/C system.
NOTE: When ambient air temperature is high, it may be necessary to
use an external cooling fan to blow air through condenser and
radiator.
4) When proper amount of refrigerant has been added, close
refrigerant container valve. Allow any refrigerant remaining in hose
to be drawn into A/C system. When low-side pressure decreases to about
30 psi (2.1 kg/cm
), close center valve on manifold gauge set. Ensure
A/C system is operating properly. Disconnect manifold gauge set.
Install service port caps. Check system for leaks. See LEAK TESTING.
GENERAL MOTORS
Manufacturer recommends using A/C Refrigerant Recovery,
Recycling And Recharging (ACR4) System (J-39500). The ACR4 system ha\
s
one filtering cycle during recovery plus an automatic multiple pass
filtering during evacuation cycle. Follow manufacturer's instructions
provided with ACR4 equipment being used.
JEEP
Connect recovery/recycling equipment, meeting SAE standard
J1991 or J2210, to vehicle. Charge A/C system to specifications, using
equipment manufacturer's instructions.
LEAK TESTING
TYPES OF LEAK DETECTORS
Bubble Solution Detector
This is a solution applied externally at suspected leak
points. Leaking refrigerant will cause the detector to form bubbles
and foam. A soap and water solution also works well.
Dye Solution
This is a colored solution that may be introduced into the
A/C system. The dye will show up and color components at leak points.
Some manufacturers offer refrigerant containing a Red dye. This dye-
containing refrigerant is installed by normal charging procedures.
Other dye solutions are visible with a Black light only.
Electronic Leak Detector
This instrument will draw in any leaking refrigerant through
a test probe, and then sound an audible signal or create a flashing
light if refrigerant is found. It is the most sensitive of the leak
detectors used. Leak detectors are sensitive to windshield washing
solutions, many solvents and cleaners, and some adhesives. Ensure
surfaces near test areas are clean and dry to prevent false signal or
detector damage. Liquids ingested into detector will damage detector.
See Fig. 24 .