1999 DODGE RAM check engine

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.

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

1) Manufacturer recommends flushing contaminated system using
one gallon of Ford A/C System Flushing Solvent (F4AZ-19579-A), a
Filter (FL-1A), an A/C Flusher Fitting Kit (014-00992). DO NOT reuse\
flushing solvent and filter, they are intended to be used on one
vehicle only.
2) Discharge A/C system, using approved refrigerant
recovery/recycling equipment. Flush specified A/C components using A/C
System Flusher (014-00991), according to manufacturer's operating
instructions.
3) If an A/C system flusher is not available to clean A/C
system, an in-line filter kit can be used. Filter kit is installed
before replacement compressor, accumulator/receiver-drier, muffler,
and thermal expansion valve/fixed orifice tube have been installed.
4) Filter kits are used with either a rubber lined suction
hose or with a nylon lined suction hose located between compressor and
evaporator. Rubber lined hose has a wall thickness of 1/4" and nylon
lined hose has a wall thickness of 1/8". See Fig. 22.
5) The filter kit for either type hose has 2 filters. A
temporary pancake filter and a permanent in-line suction filter.
Pancake filter is temporarily installed between condenser and
condenser-to-evaporator line. See Fig. 23. Permanent filter is
installed in suction line between accumulator and compressor.
6) Install replacement components (compressor, accumulator
and fixed orifice) with correct amount of refrigerant oil. See
COMPRESSOR REFRIGERANT OIL CHECKING article.
7) Cut suction hose between compressor and accumulator
(closer to compressor). Remove a length of suction hose to accommodate\
suction filter. Measure side wall of suction hose and install
appropriate filter with "O" rings and filter clamps. If side wall is
1/4", use in-line filter labeled USE WITH RUBBER INNER LINED HOSE. If
side wall is 1/8", use in-line filter labeled USE WITH NYLON INNER
LINED HOSE. Ensure arrow on filter is pointing in direction of
refrigerant flow. Tighten hose clamps to 54 INCH lbs. (6 N.m). See
Fig. 22 .
8) Install pancake filter in liquid line between condenser
and condenser-to-evaporator line. Ensure filter inlet (label) is
toward condenser. Evacuate, charge, and leak test A/C system. See
EVACUATING A/C SYSTEM, CHARGING A/C SYSTEM and LEAK TESTING. Check
filters and hoses for clearance from other engine components. Use tie
straps if necessary.
9) Place an external cooling fan in front of radiator. Select
MAX A/C operation and set blower motor speed to maximum. Start engine
and allow to idle. Ensure A/C is operating properly. Slowly increase
engine speed to 800 RPM, then 1000 RPM, and then to 1200 RPM. With
engine speed set to 1200 RPM, operate engine for one hour with A/C
system operating.
10) Stop engine. Discharge A/C system, using approved
refrigerant recovery/recycling equipment. Remove pancake filter, hoses
and fittings. Discard pancake filter. Reconnect liquid line, evacuate,
charge, and leak test A/C system. Ensure A/C system is operating
properly.

vacuum reading of 26 in. Hg or more. Close all valves and turn vacuum
pump off. Observe vacuum gauge, go to next step.
2) If A/C system maintains specified vacuum for 5 minutes,
open low-side and high-side valves, restart vacuum pump and operate
for an additional 10 minutes. Close all valves. Turn vacuum pump off
and disconnect pump.
3) If A/C system cannot get to or maintain specified vacuum,
check for a defective vacuum pump or leak in A/C system or gauge set.
See LEAK TESTING. Repair or replace components as necessary.
CHARGING A/C SYSTEM
* PLEASE READ THIS FIRST *
CAUTION: During charging of A/C system, refrigerant container must be
in an upright position. If refrigerant container is
upside down, compressor may be damaged by liquid refrigerant
drawn into A/C system.
CHRYSLER CORP.
Avenger 2.0L & Sebring Coupe 2.0L
1) Ensure A/C system has no leaks and has been evacuated. See
EVACUATING A/C SYSTEM and LEAK TESTING. Locate sight glass on
receiver-drier and ensure it is clean. Close low-pressure adapter
valve and remove from manifold gauge set.
2) Connect low-pressure adapter valve to refrigerant
container and open container valve. Ensure Blue charging hose is
properly connected to vehicle low-pressure service valve. Open adapter
valve.
3) If refrigerant is not drawn in, fully close adapter valve
and check for hose connection leaks. If leak is detected, retighten
connections and repeat A/C system evacuation. See EVACUATING A/C
SYSTEM.
4) If refrigerant is drawn in, start engine. Turn A/C on and
set temperature control to maximum cold and blower motor to low speed.
Operate engine at 1500 RPM. As refrigerant is drawn into system, foam
or bubbles will appear in sight glass.
5) System charge will be close to full when sight glass is
clear, compressor clutch is engaged, and compressor suction and
discharge line temperatures are similar. System charge will be
complete when sight glass is clear, compressor clutch is engaged,
compressor discharge line is warm and suction line is cool.
6) When proper amount of refrigerant has been added, stop
engine. Close refrigerant container and adapter valve, and disconnect
gauge set.
Breeze, Cirrus, Concorde, Intrepid, LHS, Stratus & 300M (Scan
Tool Method)
1) Attach Diagnostic Readout Box (DRB) to Data Link Connecto\
r
(DLC). Set DRB (scan tool) to PARTIAL CHARGE TEST. Attach clamp-on
Thermocouple (80PK-1A) to liquid line, as close to condenser outlet as\
possible.
2) Set parking brake, and place transaxle in Park position.
Start engine and allow to idle. Set A/C controls to outside air, panel
mode, full cool, and high blower speed. Turn A/C on, and open vehicle
windows. Operate A/C system for a few minutes to allow system to
stabilize.
3) Place cardboard over front grille area, to block airflow
through part of condenser, to set A/C system pressure to 260 psi (18.3
kg/cm
). This will stop cooling fans from alternating speeds and
maintain constant pressure.

4) Scan tool will automatically calculate system charge.
Depending on system charge condition, corrections are made 2 ounces at
a time. Each time a correction is made, recheck readings to ensure
proper charge. For system refrigerant capacity, see REFRIGERANT OIL &
REFRIGERANT SPECIFICATIONS article.
Breeze, Cirrus, Concorde, Intrepid, LHS, Stratus & 300M
(Manifold Gauge Set Method)
1) Attach clamp-on Thermocouple (80PK-1A) to liquid line, as\
close to condenser outlet as possible. Attach manifold gauge set to
vehicle.
2) Set parking brake, and place transaxle in Park position.
Start engine and allow to idle. Set A/C controls to outside air, panel
mode, full cool, and high blower speed. Turn A/C on, and open windows.
Operate system for a few minutes to allow system to stabilize.
3) Place cardboard over front grille area, to block airflow
through part of condenser, to set A/C pressure to 260 psi (18.3
kg/cm
). This will stop cooling fans from alternating speeds and
maintain constant pressure.
4) Record temperature reading at liquid line and discharge
pressure reading on gauges. Compare readings with values in
REFRIGERANT CHARGE LEVEL table.
5) Depending on system charge condition, corrections are made
2 ounces at a time. Each time a correction is made, recheck readings
to ensure proper charge. For system refrigerant capacity, see
REFRIGERANT OIL & REFRIGERANT SPECIFICATIONS article.
REFRIGERANT CHARGE LEVEL









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Liquid Line Temp. ( 1) Discharge PressureF (C) psi (kg/cm)
40 (4.4) ........................................... 53-75 (3.7-5.3\
)
60 (15.6) ......................................... 81-104 (5.7-7.3\
)
80 (26.7) ....................................... 111-142 (7.8-10.0\
)
100 (37.8) ..................................... 156-194 (11.0-13.6\
)
120 (48.9) ..................................... 208-259 (14.6-18.2\
)
140 (60.0) ..................................... 272-331 (19.1-23.3\
)
160 (71.1) ..................................... 353-420 (24.8-29.5\
)
180 (82.2) ..................................... 447-516 (31.4-36.3\
)
( 1) - When pressure is lower than specified, system is undercharged.
When pressure is higher than specified, system is overcharged.









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All Other Models
Ensure A/C system has been checked for leaks and evacuated.
See EVACUATING A/C SYSTEM and LEAK TESTING. Charge A/C system to
specifications. For system refrigerant capacity, see REFRIGERANT OIL &
REFRIGERANT SPECIFICATIONS article.
FORD MOTOR CO.
1) If using approved Recovery/Recycling/Charging Center (023-\
00105 or 023-00150), connect to high-side and low-side service valves.
See SERVICE VALVE LOCATIONS under SYSTEM SERVICE VALVES. Operate
charging center according to manufacturer's instructions. Charge
system with specified amount of refrigerant and refrigerant oil. See
REFRIGERANT OIL & REFRIGERANT SPECIFICATIONS article. Check amount of
refrigerant oil in system before adding oil. See COMPRESSOR
REFRIGERANT OIL CHECKING article.
2) If using manifold gauge set, connect to high-side and low-
side service valves. See SERVICE VALVE LOCATIONS under SYSTEM SERVICE

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 .

Fig. 24: Electronic Leak Detector
PREPARATION FOR LEAK TESTING
Connect manifold gauge set to air conditioning system. Ensure
low-side and high-side gauge set valves are closed. Check system
pressure. It should be at least 50 psi (3.5 kg/cm
). If system is
empty, evacuate A/C system and apply 28 in. Hg of vacuum. If system
holds vacuum for 15 minutes there most likely are no leaks present. If
low, add just enough refrigerant (about 10 ounces) to bring system to
50 psi (3.5 kg/cm
).
Ensure all joints, connections, and fittings are free of oil
dirt and other contaminants. Using a refrigerant leak detector, check
all refrigerant line connections for leaks. Check condenser and
compressor seal area.
Start engine and allow to idle. Operate A/C system for about
5 minutes. Set A/C controls to outside air, and high blower speed.
Turn A/C on, and open vehicle windows. Turn engine off and wait 2-7
minutes. Refrigerant is heavier than air. Always check for leaks at
bottom of refrigerant lines and components. Refrigerant oil will leak
with refrigerant. Visually check all connections and compressor clutch
area for oil stains. If compressor shaft seal is leaking, a fresh oil
streak will normally be seen on underside of hood, above compressor
clutch.
Always perform leak testing after A/C service. Move
refrigerant leak detector slowly to check for leaks, as leaks will not

be detected if leak testing is performed too quickly.
BUBBLE DETECTOR LEAK TESTING PROCEDURE
This leak detection method is recommended when it is
impossible or difficult to determine the exact location of the leak
using other methods. Although commercial bubble detectors are more
effective, household soap solutions may be used.
Using the dauber that comes with the commercial soap
solution, apply the solution to all joints, connections, fittings or
controls where a leak might be suspected. If high-suds household
solutions are used, apply them with a small brush. Wherever bubbles
form, leaks are present and must be repaired. check the entire system
as there may be more than one leak.
ELECTRONIC LEAK TESTING PROCEDURE
NOTE: Some electronic leak detectors will function on only R-12
systems or on only R-134a systems, and some will function on
both R-12 and R-134a systems. Familiarize yourself with the
tester being used and know what type of system you are leak
testing.
Electronic leak detectors should be used in well ventilated
areas. Avoid using them around explosive gases. Always follow
manufacturer's instructions for the specific tester being used. If
none are available, proceed as follows:
1) Turn all controls and detector sensitivity knob to OFF
position or zero setting. Connect leak detector to an approved source
of power. Turn switch ON, and allow unit to warm up for approximately
5 minutes.
2) Check operation of tester by positioning probe in a
reference source where refrigerant is known to be present in small
amounts. Adjust controls and sensitivity knob until detector reacts
properly. Move probe away from refrigerant source and the reaction
should stop. If it continues, adjust the sensitivity knob to a lower
setting.
3) When tester reacts properly, leak test air conditioning
system by moving probe UNDER all components, fittings and connections.
Keep the probe moving. To check evaporator insert probe into drain
tube opening or a heater duct. DO NOT allow probe to contact
refrigerant or refrigerant oil. When leaks are found, repair them as
necessary. Keep in mind that there may be more than one leak.
DYE SOLUTION LEAK TESTING PROCEDURES
CAUTION: Dye-charged refrigerant cans are available to be used as
internal leak detectors. The use of this type of solution may
void some manufacturer's warranties. Be sure to check with
the A/C system manufacturer concerning the use of dye-charged
leak detectors. Dyes which work in R-12 systems will not work
in R-134a systems.
The following procedure is for introducing a dye solution,
not dye-charged refrigerant, into A/C system.
1) Connect manifold gauge set to air conditioning system in a
normal manner. Remove center hose from manifold gauge set, and replace
it with a short piece (6" long) of 1/4" tubing using two 1/4" flare
nuts. Connect a container of dye solution to the tubing.
2) Connect one end of gauge set center hose to dye solution
container. Connect a container of refrigerant to the other end of the
hose. Operate engine at idle speed. Set the air conditioning system
for maximum cooling. Slowly open the low-side hand valve to allow the