air DODGE RAM 1500 1998 2.G Workshop Manual
[x] Cancel search | Manufacturer: DODGE, Model Year: 1998, Model line: RAM 1500, Model: DODGE RAM 1500 1998 2.GPages: 2627
Page 2368 of 2627

PAINT
TABLE OF CONTENTS
page page
PAINT
SPECIFICATIONS - PAINT CODES..........73
PAINT CODE
DESCRIPTION.........................73
BASECOAT/CLEARCOAT FINISH
DESCRIPTION.........................73PAINT TOUCH-UP
DESCRIPTION.........................74
STANDARD PROCEDURE - PAINT TOUCH-UP . 74
FINESSE SANDING/BUFFING & POLISHING
DESCRIPTION.........................74
PAINT
SPECIFICATIONS - PAINT CODES
NOTE: Because of late model changes to the avail-
able paint colors (Refer to VEHICLE DATA/VEHICLE
INFORMATION/VEHICLE CERTIFICATION LABEL -
DESCRIPTION) or (Refer to VEHICLE DATA/VEHI-
CLE INFORMATION/BODY CODE PLATE - DESCRIP-
TION) for the correct paint codes for each vehicle.
(Refer to 23 - BODY/PAINT/PAINT CODE - DESCRIP-
TION)
EXTERIOR COLORS
EXTERIOR COLOR DAIMLERCHRYSLER
CODE
Deep Molten Red
PearlcoatBR8
Flame Red Clearcoat PR4
Light Almond Pearl
Metallic ClearcoatZKJ
Atlantic Blue Pearlcoat ZBJ
Patriot Blue Pearlcoat WBT/WB7
Graphite Metallic
ClearcoatZDR
Bright Silver Metallic
ClearcoatWSB/WS2
Black Clearcoat DX8
Bright White Clearcoat GW7
Timberline Green AGW
INTERIOR COLORS
INTERIOR COLOR DAIMLERCHRYSLER
CODE
Taupe L5
Dark Slate Gray DV
PAINT CODE
DESCRIPTION
Exterior vehicle body colors are identified on the
Vehicle Certification Label (Refer to VEHICLE
DATA/VEHICLE INFORMATION/VEHICLE CERTI-
FICATION LABEL - DESCRIPTION) or the Body
Code Plate (Refer to VEHICLE DATA/VEHICLE
INFORMATION/BODY CODE PLATE - DESCRIP-
TION). The first digit of the paint code listed on the
vehicle indicates the sequence of application, i.e.: P =
primary coat, Q = secondary coat. The color names
provided in the Paint and Trim Code Description
chart are the color names used on most repair prod-
uct containers. (Refer to 23 - BODY/PAINT - SPECI-
FICATIONS)
BASECOAT/CLEARCOAT
FINISH
DESCRIPTION
The original equipment finish is a multi step pro-
cess that involves cleaning, applying electro de-posi-
tion (E-coat), anti-chip primer, basecoat, and
clearcoat steps.
On most vehicles a two-part paint application
(basecoat/clearcoat) is used. Color paint that is
applied to primer is called basecoat. The clear coat
protects the basecoat from ultraviolet light and pro-
vides a durable high-gloss finish.
DRPAINT 23 - 73
Page 2369 of 2627

CAUTION: Do not use abrasive chemicals or com-
pounds on painted surfaces. Damage to finish can
result.
Do not use harsh alkaline based cleaning solvents
on painted surfaces. Damage to finish or color can
result.
PAINT TOUCH-UP
DESCRIPTION
When a painted metal surface has been scratched
or chipped, it should be touched-up as soon as possi-
ble to avoid corrosion. For best results, use MOPARt
Scratch Filler/Primer, Touch-Up Paints and Clear Top
Coat. (Refer to VEHICLE DATA/VEHICLE INFOR-
MATION/BODY CODE PLATE - DESCRIPTION) for
Body Code Plate information.
WARNING: USE AN OSHA APPROVED RESPIRATOR
AND SAFETY GLASSES WHEN SPRAYING PAINT
OR SOLVENTS IN A CONFINED AREA. PERSONAL
INJURY CAN RESULT.
STANDARD PROCEDURE - PAINT TOUCH-UP
(1) Scrape loose paint and corrosion from inside
scratch or chip.
(2) Clean affected area with MOPARtTar/Road
Oil Remover or equivalent, and allow to dry.
(3) Fill the inside of the scratch or chip with a coat
of filler/primer. Do not overlap primer onto good sur-
face finish. The applicator brush should be wet
enough to puddle-fill the scratch or chip without run-
ning. Do not stroke brush applicator on body surface.
Allow the filler/primer to dry hard.
(4) Cover the filler/primer with color touch-up
paint. Do not overlap touch-up color onto the original
color coat around the scratch or chip. Butt the new
color to the original color, if possible. Do not stroke
applicator brush on body surface. Allow touch-up
paint to dry hard.(5) On vehicles without clearcoat, the touch-up
color can be lightly finesse sanded (1500 grit) and
polished with rubbing compound.
(6) On vehicles with clearcoat, apply clear top coat
to touch-up paint with the same technique as
described in Step 4. Allow clear top coat to dry hard.
If desired, Step 5 can be performed on clear top coat.
WARNING: AVOID PROLONGED SKIN CONTACT
WITH PETROLEUM OR ALCOHOL ± BASED CLEAN-
ING SOLVENTS. PERSONAL INJURY CAN
RESULT.AVOID PROLONGED SKIN CONTACT WITH
PETROLEUM OR ALCOHOL ± BASED CLEANING
SOLVENTS. PERSONAL INJURY CAN RESULT.
FINESSE SANDING/BUFFING &
POLISHING
DESCRIPTION
CAUTION: Do not remove more than .5 mils of
clearcoat finish, if equipped. Basecoat paint must
retain clearcoat for durability.
Use a Paint Thickness Gauge #PR-ETG-2X or equiv-
alent to determine film thickness before and after
the repair.
Minor acid etching, orange peel, or smudging in
clearcoat or single-stage finishes can be reduced with
light finesse sanding, hand buffing, and polishing.If
the finish has been finesse sanded in the past,
it cannot be repeated. Finesse sanding opera-
tion should be performed by a trained automo-
tive paint technician.
23 - 74 PAINTDR
BASECOAT/CLEARCOAT FINISH (Continued)
Page 2381 of 2627

STATIONARY GLASS
TABLE OF CONTENTS
page page
BACKLITE
REMOVAL.............................86
INSTALLATION.........................86
BACKLITE VENT GLASS
REMOVAL.............................87
INSTALLATION.........................87WINDSHIELD
WARNING
WINDSHIELD SAFETY PRECAUTIONS.....88
REMOVAL.............................88
INSTALLATION.........................88
BACKLITE
REMOVAL
It is difficult to salvage the backlite during the
removal operation. The backlite is part of the struc-
tural support for the roof. The urethane bonding
used to secure the glass to the fence is difficult to cut
or clean from any surface. Since the molding is set in
urethane, it is unlikely it would be salvaged. Before
removing the backlite, check the availability from the
parts supplier.
The backlite is attached to the window frame with
urethane adhesive. The urethane adhesive is applied
cold and seals the surface area between the window
opening and the glass. The primer adheres the ure-
thane adhesive to the backlite.
(1) Roll down door glass.
(2) Remove headliner. (Refer to 23 - BODY/INTE-
RIOR/HEADLINER - REMOVAL).
(3) On standard cab models remove the upper
b-pillar trim. (Refer to 23 - BODY/INTERIOR/B-PIL-
LAR UPPER TRIM - REMOVAL)
(4) On quad cab models remove the upper c-pillar
trim. (Refer to 23 - BODY/INTERIOR/C-PILLAR
UPPER TRIM - REMOVAL)
(5) Bend backlite retaining tabs (Fig. 1) inward
against glass.
(6) Disconnect the rear window defogger electrical
connector, if equipped.
(7) Using a suitable pneumatic knife from inside
the vehicle, cut urethane holding backlite frame to
opening fence.
(8) Separate glass from vehicle.
INSTALLATION
(1) Clean urethane adhesive from around backlite
opening fence.
(2) If necessary, apply black-out primer to outer
edge of replacement backlite frame.(3) If black-out primer was pre-applied on backlite,
clean bonding surface with Isopropyl alcohol and
clean lint free cloth. Allow 3 minutes for drying time.
(4) Apply black-out primer to backlite opening
fence.
(5) Apply a 13 mm (0.5 in.) bead of urethane
around the perimeter of the window frame bonding
surface (Fig. 2).
(6) Set glass on lower fence and move glass for-
ward into opening (Fig. 3).
(7) Firmly push glass against rear window glass
opening fence.
(8) Bend tabs around edges of backlite opening
fence to retain glass.
(9) Clean excess urethane from exterior with
MOPARt, Super Clean or equivalent.
(10) Allow urethane to cure at least 24 hours (full
cure is 72 hours).
(11) Water test to verify repair before returning
vehicle to service.
(12) Connect the rear window defogger electrical
connector, if equipped.
Fig. 1 Backlite Tabs
1 - BACKLITE
2-TAB
23 - 86 STATIONARY GLASSDR
Page 2384 of 2627

and 25 mm (1 in.) on the bottom of windshield. Allow
at least three minutes drying time.
(6) Locatenewsupport spacers on support brack-
ets and adjust to lowest height. (Fig. 5)
(7) Position seven new foam spacers on the inside
surface of the windshield, flush with the lower and
side edges. (Fig. 7)
(8) Position three new foam spacers on the inside
surface of the windshield, at a minimum distance of
3 mm (0.12 in.) from the top edge of the windshield.
(Fig. 7)
(9) Apply a 13 mm (1/2 in.) high and 10 mm (3/8
in.) wide bead of urethane around the perimeter of
windshield. At the top, apply the bead 7 mm (1/4 in.)
inboard from the glass edge. On the other three sides
apply the bead 14 mm (0.55 in.) inboard from the
glass edge. The urethane bead should be shaped in a
triangular cross-section, this can be achieved by
notching the tip of the applicator (Fig. 8).
(10) Install the a-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - INSTALLATION)
(11) With the aid of a helper, position the wind-
shield over the windshield opening. Align the refer-
ence marks at the bottom of the windshield to the
support spacers.
(12) Slowly lower windshield glass to the fence
opening guiding the lower corners into proper posi-
tion. Beginning at the bottom and continuing to the
top, push glass onto fence along the A-Pillars. Push
windshield inward to the fence at the bottom corners
(Fig. 9).
(13) Push windshield upward, setting the wind-
shield to roof gap to 1.5 mm (0.06 in.) to 3 mm (0.12
in.) and ratchet up the adjustable support brackets.
(14) Using clean water, lightly mist the support
spacers.
(15) Clean excess urethane from exterior with
MOPARtSuper Clean or equivalent.
(16) Install cowl grill. (Refer to 23 - BODY/EXTE-
RIOR/COWL GRILLE - INSTALLATION).
(17) Install rear view mirror support bracket.
(Refer to 23 - BODY/INTERIOR/REAR VIEW MIR-
ROR - INSTALLATION).
(18) Install rear view mirror. (Refer to 23 - BODY/
INTERIOR/REAR VIEW MIRROR - INSTALLA-
TION).
(19) Install the a-pillar weatherstrip retainer.
(Refer to 23 - BODY/WEATHERSTRIP/SEALS/A-
PILLAR WEATHERSTRIP RETAINER - INSTALLA-
TION)
(20) After urethane has cured, remove tape strips
and water test windshield to verify repair.
Fig. 5 CENTER WINDSHIELD AND MARK AT
SUPPORT
1 - WINDSHIELD
2 - INDEX MARKS
3 - SUPPORT SPACERS
Fig. 6 WORK SURFACE SET UP
1 - WINDSHIELD AND MOLDINGS
2 - URETHANE BEAD AROUND GLASS 7mm (0.3 in.) FROM
EDGE
3 - BLOCKS
DRSTATIONARY GLASS 23 - 89
WINDSHIELD (Continued)
Page 2415 of 2627

WELD LOCATIONS
SPECIFICATIONS
INDEX
DESCRIPTION FIGURE
FENDER BRACE, CLOSURE TUBE AND FRAME MOUNTING BRACKET TO FRONT
FENDER SUPPORT, FRONT FENDER AND RADIATOR TUBE31
STEERING COLUMN SUPPORT, CONNECTOR WIRING BRACKET AND WELD NUTS
TO LOWER PLENUM PANEL32
WIPER ATTACHING WELD NUTS AND VACUUM RESERVOIR ATTACHING STUDS TO
COWL PAR PANEL33
DASH PANEL TO FRONT FLOOR PAN 34
DASH PANEL TO LOWER PLENUM PANEL 35
LOWER PLENUM PANEL TO COWL BACK PANEL 36
FRONT FENDER AND RADIATOR TUBE DASH PANEL, INSTRUMENT PANEL
MOUNTING BRACKET, AND WELD NUTS TO COWL SIDE PANEL - LEFT SIDE37
DASH PANEL, LOWER PLENUM PANEL AND COWL PANEL BAR TO COWL SIDE
PANEL - LEFT SIDE38
FRONT FENDER AND RADIATOR TUBE DASH PANEL, INSTRUMENT PANEL
MOUNTING BRACKET AND WELD NUTS TO COWL SIDE PANEL - RIGHT SIDE39
DASH PANEL, LOWER PLENUM PANEL AND COWL PANEL BAR TO COWL SIDE
PANEL - RIGHT SIDE40
REINFORCEMENT AND HEADLAMP MOUNTING PANEL TO OUTER FENDER PANEL 41
SEAT MOUNTING FRONT BRACKETS TO SEAT MOUNTING FRONT CROSSMEMBER
TO FRONT FLOOR PAN42
AIR BAG MODULE BRACKET SHIFTER MOUNTING PLATE AND REAR FLOOR PANE
TO FRONT FLOOR PAN43
RIGHT TO LEFT REAR FLOOR CROSSMEMBER AND RIGHT TO LEFT SEAT
MOUNTING CROSSMEMBER44
REAR FLOOR CROSSMEMBER, SEAT MOUNTING CROSSMEMBER AND
UNDERBODY SUPPORT TO FLOOR SILL45
SEAT MOUNTING FRONT CROSSMEMBER TO FRONT FLOOR PAN TO UNDERBODY
SUPPORT46
FRONT SEAT MOUNTING CROSSMEMBERS TO FRONT SEAT MOUNTING BRACKET
TO FRONT FLOOR PAN47
REAR FLOOR CROSSMEMBERS TO REAR FLOOR PAN 48
FLOOR SILL TO FRONT SEAT MOUNTING CROSSMEMBER, FRONT AND REAR
FLOOR PAN49
AIR BAG MODULE BRACKET, SHIFTER MOUNTING PLATE AND FRONT SEAT
MOUNTING CROSSMEMBER TO FRONT FLOOR PAN50
REAR SEAT MIDDLE MOUNTING PLATE TO REAR FLOOR PAN TO FRONT FLOOR
PA N51
REAR FLOOR CROSSMEMBER, SEAT MOUNTING CROSSMEMBER AND
UNDERBODY SUPPORT TO FLOOR SILL52
LEFT REAR CROSSMEMBER TO RIGHT REAR CROSSMEMBER TO REAR FLOOR
PA N53
23 - 120 BODY STRUCTUREDR
Page 2427 of 2627

Fig. 43 AIR BAG MODULE BRACKET - STANDARD CAB
23 - 132 BODY STRUCTUREDR
WELD LOCATIONS (Continued)
Page 2433 of 2627

Fig. 50 AIR BAG MODULE BRACKET - QUAD CAB
23 - 138 BODY STRUCTUREDR
WELD LOCATIONS (Continued)
Page 2488 of 2627

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING
SYSTEM REQUIREMENTS...............1
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
OPERATION - HEATER AND AIR
CONDITIONER........................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE.......................3DIAGNOSIS AND TESTING - HEATER
PERFORMANCE TEST..................6
SPECIFICATIONS - A/C SYSTEM............7
CONTROLS.............................9
DISTRIBUTION..........................26
PLUMBING.............................41
HEATING & AIR
CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the heating,
ventilation and air conditioning (HVAC) system, the
engine cooling system must be properly maintained.
The use of a bug screen is not recommended. Any
obstructions in front of the radiator or A/C condenser
will reduce the performance of the A/C and engine
cooling systems.
The engine cooling system includes the radiator,
thermostat, radiator hoses and the engine coolant
pump. Refer to Cooling for more information before
opening or attempting any service to the engine cool-
ing system.
DESCRIPTION - HEATER AND AIR
CONDITIONER
A manually controlled single zone type heating-air
conditioning system or a manually controlled dual
zone type heating-air conditioning system is available
on this model.
All vehicles are equipped with a common heater,
ventilation and air conditioning (HVAC) housing (Fig.
1). The system combines air conditioning, heating,
and ventilating capabilities in a single unit housing
mounted within the passenger compartment under
the instrument panel. The HVAC housing includes:
²Blower motor
²Blower motor resistor block²Heater core
²Evaporator coil
²Blend door and actuator
²Defrost door and actuator
²Mode door and actuator
²Recirculation door and actuator
Based upon the system and mode selected, condi-
tioned air can exit the HVAC housing through one or
a combination of the three main housing outlets:
defrost, panel or floor. The defrost outlet is located on
the top of the housing, the panel outlet is located on
the face of the housing and the floor outlet is located
on the bottom of the housing. Once the conditioned
air exits the unit housing, it is further directed
through molded plastic ducts to the various outlets in
the vehicle interior. These outlets and their locations
are as follows:
²Defroster Outlet- A single large defroster out-
let is located in the center of the instrument panel
top cover, near the base of the windshield.
²Side Window Demister Outlets- There are
two side window demister outlets, one is located at
each outboard end of the instrument panel top cover,
near the belt line at the A-pillars.
²Panel Outlets- There are four panel outlets in
the instrument panel, one located near each outboard
end of the instrument panel facing the rear of the
vehicle and two located near the top of the instru-
ment panel center bezel.
²Front Floor Outlets- There are two front floor
outlets, one located above each side of the floor panel
center tunnel near the dash panel.
OPERATION - HEATER AND AIR CONDITIONER
The heating and air conditioning systems pulls
outside (ambient) air through the cowl opening at the
base of the windshield, then into the plenum cham-
DRHEATING & AIR CONDITIONING 24 - 1
Page 2489 of 2627

ber above the heating, ventilation and air condition-
ing (HVAC) housing. On models equipped with air
conditioning, the air passes through the evaporator
coil. Air flow can be directed either through or
around the heater core. This is done by adjusting the
blend door with the temperature control knob on the
A/C-heater control located the instrument panel. The
air flow can then be directed from the panel, floor
and defrost outlets in various combinations using the
mode control knob located on the A/C-heater control.
Air flow velocity can be adjusted with the blower
speed selector located on the A/C-heater control.
NOTE: It is important to keep the air intake opening
clear of debris. Leaf particles and other debris that
is small enough to pass through the cowl opening
screen can accumulate within the HVAC housing.
The closed, warm, damp and dark environment cre-
ated within the housing is ideal for the growth of
certain molds, mildews and other fungi. Any accu-mulation of decaying plant matter provides an addi-
tional food source for fungal spores, which enter
the housing with the fresh intake-air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during heater-A/C
operation if the air intake opening is not kept clear
of debris.
The heater and air conditioning systems are blend-
air type systems. In a blend-air system, a blend door
controls the amount of unconditioned air (or cooled
air from the evaporator on models with air condition-
ing) that is allowed to flow through, or around, the
heater core. A temperature control knob determines
the discharge air temperature by actuating an elec-
tric motor, which operates the blend door. This allows
an almost immediate control of the output air tem-
perature of the system.
On all models, the outside air intake can be shut
off by selecting the Recirculation Mode with the
mode control knob. This will operate a electric actu-
ated recirculation air door that closes off the outside
fresh air intake and recirculates the air that is
already inside the vehicle.
The air conditioning compressor can be engaged in
any mode by pressing the snowflake, A/C on/off but-
ton. It can also be engaged by placing the mode con-
trol in the mix to defrost positions. This will remove
heat and humidity from the air before it is directed
through or around the heater core. The mode control
knob on the A/C-heater control is used to also direct
the conditioned air to the selected system outlets.
The mode control switch uses an electric motor to
control the mode doors.
The defroster outlet receives airflow from the
HVAC housing through the molded plastic defroster
duct, which connects to the HVAC housing defroster
outlet. The airflow from the defroster outlets is
directed by fixed vanes in the defroster outlet grilles
and cannot be adjusted. The defroster outlet grilles
are integral to the instrument panel top cover.
The side window demister outlets receive airflow
from the HVAC housing through the molded plastic
defroster duct and two molded plastic demister ducts.
The airflow from the side window demister outlets is
directed by fixed vanes in the demister outlet grilles
and cannot be adjusted. The side window demister
outlet grilles are integral to the instrument panel.
The demisters direct air from the HVAC housing
through the outlets located on the top corners of the
instrument panel. The demisters operate when the
mode control knob is positioned in the floor-defrost
and defrost-only settings. Some air may be noticeable
from the demister outlets when the mode control is
in the bi-level to floor positions.
Fig. 1 HVAC Housing - Dual Zone Shown, Single
Zone Typical
1 - NUT
2 - PASSENGER BLEND DOOR ACTUATOR
3 - NUT
4 - INLET BAFFLE
5 - RECIRCULATION DOOR ACTUATOR
6 - RECIRCULATION DOOR
7 - DRIVER SIDE BLEND DOOR ACTUATOR
8 - HVAC HOUSING
9 - BOLT
10 - DEFROSTER DOOR ACTUATOR
11 - MODE DOOR ACTUATOR
24 - 2 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)
Page 2490 of 2627

The panel outlets receive airflow from the HVAC
housing through a molded plastic main panel duct,
center panel duct and two end panel ducts. The two
end panel ducts direct airflow to the left and right
instrument panel outlets, while the center panel duct
directs airflow to the two center panel outlets. Each
of these outlets can be individually adjusted to direct
the flow of air.
The floor outlets receive airflow from the HVAC
housing through the floor distribution duct. The front
floor outlets are integral to the molded plastic floor
distribution duct, which is secured to the bottom of
the housing. The floor outlets cannot be adjusted.
The air conditioner for all models is designed for
the use of non-CFC, R-134a refrigerant. The air con-
ditioning system has an evaporator to cool and dehu-
midify the incoming air prior to blending it with the
heated air. This air conditioning system uses a fixed
orifice tube in the liquid line near the condenser out-
let tube to meter refrigerant flow to the evaporator
coil. To maintain minimum evaporator temperature
and prevent evaporator freezing, a evaporator tem-
perature sensor is used. The JTEC control module is
programmed to respond to the evaporator tempera-
ture sensor input by cycling the air conditioning com-
pressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE
The air conditioning system is designed to remove
heat and humidity from the air entering the passen-
ger compartment. The evaporator, located in the
HVAC housing, is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins in the evaporator, moisture in the air condenses
to water, dehumidifying the air. Condensation on the
evaporator fins reduces the evaporators ability to
absorb heat. During periods of high heat and humid-
ity, an air conditioning system will be less effective.
With the instrument control set to Recirculation
mode, only air from the passenger compartment
passes through the evaporator. As the passenger com-
partment air dehumidifies, A/C performance levels
rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the air condition-
ing system. When humidity is high, the evaporator
has to perform a double duty. It must lower the air
temperature, and it must lower the temperature ofthe moisture in the air that condenses on the evapo-
rator fins. Condensing the moisture in the air trans-
fers heat energy into the evaporator fins and tubing.
This reduces the amount of heat the evaporator can
absorb from the air. High humidity greatly reduces
the ability of the evaporator to lower the temperature
of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
air conditioning system on humid days. A perfor-
mance test is the best way to determine whether the
system is performing up to standard. This test also
provides valuable clues as to the possible cause of
trouble with the air conditioning system.
PERFORMANCE TEST PROCEDURE
Review Safety Warnings and Cautions before per-
forming this procedure (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) and
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION). Air temperature in test
room and on vehicle must be 21É C (70É F) minimum
for this test.
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 tachometer and a manifold gauge set
or A/C recycling/charging station.
(2) Set the A/C-heater mode control in the Recircu-
lation Mode position, the temperature control knob in
the full cool position, and the blower motor switch to
the highest speed position.
(3) Start the engine and hold at 1,000 rpm with
the A/C compressor clutch engaged.
(4) The engine should be warmed up to operating
temperature with the doors closed and windows
open.
(5) Insert a thermometer in the driver side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) The compressor clutch may cycle, depending
upon the ambient temperature and humidity.
(7) With the compressor clutch engaged, record the
discharge air temperature and the compressor dis-
charge pressure.
(8) If the discharge air temperature fails to meet
the specifications in the A/C Performance Tempera-
ture chart, refer to the Pressure Diagnosis chart.
DRHEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)