1993 DODGE TRUCK oil temperature

•

HEATING
AND
AIR
CONDITIONING
24-17 REFRIGERANT SYSTEM SERWICE PROCEDURES

INDEX
page
Charging
the
System
19

Correcting
Low
Refrigerant
Level
.............
20
Discharging
the
System
. 19
Evacuating
the
System
19

REFRIGERANT

SAFETY
PRECAUTIONS

WARNING: EXTREME CARE MUST
BE
TAKEN
TO
PREVENT
ANY LIQUID
REFRIGERANT FROM COM­
ING
IN
CONTACT
WITH
THE
SKIN
AND
ESPE­

CIALLY
THE
EYES.
ALWAYS WEAR SAFETY
GOGGLES WHEN SERVICING
ANY
PART
OF
THE
REFRIGERANT SYSTEM.
IF EYE
CONTACT
IS

MADE,
APPLY
A
FEW
DROPS
OF
MINERAL
OIL
TO

THE
EYES
AND
FLUSH
WITH
WATER
FOR
SEV­
ERAL MINUTES.
SEEK
MEDICAL
ATTENTION
IMME­
DIATELY.

The refrigerant used
in the air
conditioner system
is Refrigerant-12 (R-12).
R-12 is
nonexplosive, non­
flammable, non-corrosive,
has
practically
no
odor
and
is heavier than
air.
Although
it is
classified
as a
safe
refrigerant, certain precautions must
be
observed
to

protect
the
parts involved
and the
person
who is

working
on the
unit. Liquid
R-12, at
normal atmo­ sphere pressures
and
temperatures, evaporates
so

quickly that
it has the
tendency
to
freeze anything
it
contacts.

WARNING:
TO
AVOID
A
DANGEROUS EXPLOSION,
NEVER
WELD
OR
STEAM CLEAN NEAR
AIR
CON­

DITIONING
LINES
OR
COMPONENTS.
DO NOT

HEAT
R-12
ABOVE
52°C (125°F)
BECAUSE
THE

CAN
MAY
EXPLODE.

The
R-12 in the
system
is
always under pressure.
Because
the
system
is
tightly sealed, heat applied
to
any part could cause this pressure
to
build
up
exces­sively.

WARNING: LARGE AMOUNTS
OF
REFRIGERANT
RELEASED
IN A
CLOSED WORK AREA
WILL
DIS­
PLACE
THE
OXYGEN
AND
CAUSE SUFFOCATION.
ALWAYS
MAINTAIN
GOOD
VENTILATION
SUR­ ROUNDING
THE
WORK AREA.

R-12
gas,
under normal conditions,
is
non-poison­

ous.
The
discharge
of R-12 gas
near
an
open flame
page
Pressure Gauge
and
Manifold
Assembly
18

Refrigerant
. 17

Refrigerant
Leak Repair Procedure
20

Service Precautions
. 17

can produce
a
very poisonous
gas
called phosgene.
Phosgene
is
generated when
a
flame-type leak detec­
tor
is
used.

CAUTION:
When charging
an A/C
system always
keep
the
tank
in an
upright position.
If the
tank
is

on
its
side
or
upside down,
liquid
refrigerant
will

enter
the
system
and may
damage
the
compressor.

In most instances, moderate heat
is
required
to

bring
the
pressure
of the
refrigerant above system
pressure when charging
or
adding refrigerant.
A

bucket
or
large
pan of hot
water,
not
over 52°C (125°F),
is all the
heat required
for
this purpose.
Do

not heat
the
refrigerant container with
a
blow torch
or
any
other means that would raise
the
temperature and pressure above this temperature.

CAUTION:
Do not
allow
liquid
refrigerant
to
touch
bright
metal.

Refrigerant will tarnish bright metal
and
chrome
surfaces. Avoid splashing
the
refrigerant
on any
sur­

face.
Refrigerant
in
combination with moisture
is

very corrosive
and can
cause extensive damage
to all

metal surfaces.

RECYCLING
(R-12) refrigerant
is a
chloroflorocarbon
(CFC)
that
can contribute
to the
depletion
of the
ozone layer
in

the upper atmosphere. Harmful radiation from
the
sun
is
filtered
out by the
ozone.
To
assist
in
protect­
ing
the
ozone layer, Chrysler Corporation recom­
mends that
an
(R-12) refrigerant recycling device
that meets
SAE
standard
J1991 be
used. Contact
an
automotive service equipment supplier
for
refriger­
ant recycling equipment that
is
available
in
your
area. Refer
to the
operating instructions provided
with
the
recycling equipment
for
proper operation.

SERVICE
PRECAUTIONS
Kinks
in the
refrigerant tubing
or
sharp bends
in

the refrigerant hose lines will greatly reduce
the ca­
pacity
of the
entire system. High pressures
are
pro­duced
in the
system when
it is
operating. Extreme
care must
be
exercised
to
make sure that
all
connec­
tions
are
pressure tight. Dirt
and
moisture
can
enter

•

HEATING
AND
AIR
CONDITIONING
24 - 19
Connect
the
compound gauge hose
to the
compres­
sor suction service valve gauge port (low-side).
Connect
the
high pressure gauge hose
to the
dis­
charge service valve gauge port (high-side). Purge
air
from
the
high side test hose
by
opening
the high side hand valve
on the
manifold
for 3 to 5
seconds.
The
center connection
on the
manifold must
be open.
Purge
air
from
the low
side test hose
by
opening
the
low
side hand valve
on the
manifold
for 3 to 5
seconds.
The
center connection
on the
manifold must
be open.
The
air
conditioning system
may be
operated with
the gauge manifold assembly connected
in
this man­
ner.
The
gauges will indicate respective operative
pressures.

DISCHARGING
THE SYSTEM
Since
the air
conditioning refrigerant system
is

pressurized,
it
will
be
necessary
to
completely dis­ charge
the
system before replacing
any
refrigerant
components.
The
procedure
is as
follows: (1) Install gauge
set as
described under manifold
gauge
set
installation. Make sure
the
gauge
set

valves
are
closed before attaching
the
hoses
to the re­

frigerant system. (2) Install
a
long hose
to the
manifold gauge
set

connector.
Run
this hose
to the oil
collector
can
near
the shop exhaust system. A good
oil
collector
can may be
made from
a
large
empty coffee
can
with
a
plastic
top.
Slit
the
plastic
top
in the
form
of a Y to
make
an
entrance
for the
refrigerant hose
and
exit
for the gas.
(3) Open
the
compressor discharge
and
suction line
pressure valves
and
discharge
the
refrigerant into
the
oil
collector
can.
Watch
to
make sure
the
hose does
not
blow
out of the
collector
can.
(4) When
the
system
has
been completely dis­
charged, measure
the
amount
of oil
collected
in the

can.
The
amount
of oil
measured should
be
added
to

the refrigerant system before
it is
charged. Discard
the used
oil. Add new oil.

EVACUATING
THE SYSTEM
Whenever
the
system
has
been opened
to the
atmo­
sphere,
it is
absolutely essential that
the
system
be

evacuated
to
remove
all the air and
moisture.
Air in

the refrigerant system causes high compressor dis­ charge pressures,
a
loss
in
system performance,
and

oxidation
of the
compressor
oil
into
gum and
varnish.
Moisture
in the
refrigerant system
can
cause
the ex­

pansion valve
to
malfunction. Under certain condi­
tions
it can
react with
the
refrigerant
to
form destructive acids.
It is
necessary
to
adhere
to the
fol­
lowing procedure
to
keep
air and
moisture
out of the
system. (1) Connect
the
manifold gauge
set to the
compres­
sor
and
long test hose from manifold gauge
set
center
connection
to
Vacuum Pump Tool C-4289. (2) Open both manifold gauge
set
valves.
(3) Start
the
vacuum pump
and
operate until
the

evaporator suction gauge registers
at
least
-88
kPag (26 inches
of
vacuum).
If at
least
-88
kPag
(26
inches
of vacuum) cannot
be
obtained, either
the
system
has

a leak
or the
vacuum pump
is
defective. Check
the

vacuum pump.
If the
pump proves
to be
functioning
properly,
the
system
has a
leak. Charge
the
system
with
1
pound
of
refrigerant. Locate
and
repair
all
leaks.
Discharge
the
refrigerant
and
evacuate
the
system.
(4) Continue
to
operate
the
pump
for at
least
5

minutes.
(5) Close manifold valves. Turn
off the
vacuum
pump
and
observe evaporator suction gauge
for 2
minutes.
The
vacuum level should remain constant.
If
the
vacuum level falls
off, the
system
has a
leak. Charge
the
system with
450 g (1
pound)
of
refriger­
ant. Locate
and
repair
all
leaks. Discharge
the
sys­
tem
and
repeat evacuation procedure.

CHARGING
THE
SYSTEM
The refrigerant system must have been evacuated
using
the
previous procedure before charging. Charge
using only
R-12
refrigerant.
R-12 is
available
in
bulk
tanks
or 437 g (14 oz.)
cans. The special refrigerant dispensing manifold per­
mits charging
3
cans
of
refrigerant
at a
time. When
using disposable cans
of
this type, carefully follow
the
can
manufacturers instructions.

WARNING: NEVER USE THESE CANS
TO
CHARGE
INTO
THE
HIGH
PRESSURE SIDE
OF
THE
SYSTEM

(COMPRESSOR
DISCHARGE PORT)
OR
INTO
A
SYSTEM
THAT
IS AT
HIGH
TEMPERATURE.
THE
HIGH
SYSTEM PRESSURES COULD
BE
TRANS­

FERRED
INTO
THE
CHARGING
CAN
CAUSING
IT

TO EXPLODE.

Keep
the
refrigerant manifold valves capped when
not
in use.
Keep
a
supply
of
extra refrigerant-can-to
refrigerant-manifold gaskets
on
hand
so the
gaskets can
be
replaced periodically. This will insure
a
good
seal without excessive tightening
of the can or the

manifold nuts.
(1) Attach center hose from manifold gauge
set to

refrigerant dispensing manifold. Turn refrigerant manifold valves completely counterclockwise
so
they are fully open. Remove protective caps from refriger­
ant manifold.
(2) Screw refrigerant cans into manifold.
Be
sure
manifold-to-can gasket
is in
place
and in
good condi­
tion. Tighten
can and
manifold nuts
to 9.5 N»m (7 ft.
lbs.) torque.

24
- 20
HEATING
AND AIR
CONDITIONING

• (3) Turn
3
refrigerant manifold valves completely
clockwise
to
puncture
the
cans
and
close
the
mani­
fold valves.
(4) Purge
the air
from
the
charging line
by
loosen­
ing
the
charging hose
at the
manifold gauge
set and

turn
one of the
refrigerant valves counterclockwise. When
the
refrigerant
gas
starts escaping from
the

loose connection, tighten
the
hose.
(5) Fully open
all 3
refrigerant manifold valves
and place
the
cans
of
refrigerant into
a pan
contain­
ing 52°C (125°F) water.
The
water will warm
the

charging
can and aid in the
transfer
of the
charge
into
the
system.
(6) Start
the
engine
and
move
the
controls
to A/C

low blower position.
The electronic temperature cycling switch will pre­
vent
the
clutch from engaging until refrigerant
is
added
to the
system.
If the
clutch does engage,
re­

place
the
switch before proceeding
any
further. (7) Charge through
the
suction side
of the
system
by slowly opening
the
suction manifold valve. Adjust
the valve
as
necessary
so
charging pressure does
not
exceed
345
kPag
(50
psig). Maintain
the
temperature
of
the
water
in the pan by
adding warm water
as

necessary. (8) Adjust
the
engine speed
to a
fast idle
of
approx­
imately
1,300 RPM.
(9) When
all 3
cans
of
refrigerant
are
completely
empty, close
the
manifold gauge
set
valves
and re­

frigerant manifold valves. The maximum refrigerant charge
is 44 oz.

REFRIGERANT
LEAK REPAIR PROCEDURE

LOST CHARGE If
the
system
has
lost
all
charge
due to a
leak: (1) Evacuate
the
system.
(2) Charge
the
system with approximately
1
pound
of refrigerant. (3) Locate
all
leaks.
(4) Repair
all
leaks.
(5) Replace filter-drier bottle.

CAUTION:
Replacement
filter-drier
units
must
be

sealed
while
in
storage.
The
drier
used
in
these

units
absorbs
and
traps
moisture
quickly
upon
ex­

posure
to the
atmosphere.
When
installing
a
drier,

have
all
tools
and
supplies ready
for
quick
reas­

sembly
to
avoid keeping
the
system open
any
longer
than
necessary.

(6) Check system
oil
level. (7) Evacuate
and
charge
the
system.
LOW CHARGE If
the
system
has not
lost
all of its
refrigerant
charge; locate
and
repair
all
leaks.
If it is
necessary
to increase
the
system pressure
to
find
the
leak
(be­
cause
of an
especially
low
charge),
add 230 g (1/2 lb)

of refrigerant.
If
there
has
been
a
significant
oil
loss,
check
the
system
oil
level.
If
leak repair
was
possible
without discharging system
and an oil
level check
was
not
necessary,
use
procedure
for
correcting
low

refrigerant level.

CORRECTING
LOW
REFRIGERANT LEVEL
Since
the
refrigeration system
is
completely sealed,
the refrigerant level will
not be low
unless there
is a
leak
in the
system. Before adding refrigerant where
the
cause
of a low

level
is not
known,
the
system should
be
tested
for

leaks.
Assuming that leaks have been corrected without
discharging
the
system, proceed with partial charge.
Install
and
connect manifold gauge
set.
(1) Close both manifold gauge
set
valves. Open
manifold gauge
set
needle valve.
(2) Connect
the
suction gauge test hose
to the
suc­
tion service port
of the
compressor. Connect
the
dis­ charge gauge test hose
to the
discharge service port. (3) Connect
an end of
long test hose
to the
center
manifold outlet,
and
other
end to
refrigerant dispens­ ing manifold. (4) Close
the 2
dispensing manifold valves
and

open remaining dispensing manifold valve. Remove
protective
cap
from opened valve.

WARNING: NEVER
USE
THESE CANS
TO
CHARGE
INTO
THE
HIGH
PRESSURE SIDE
OF
THE
SYSTEM

(COMPRESSOR
DISCHARGE
PORT)
OR
INTO
A
SYSTEM
THAT
IS AT
HIGH
TEMPERATURE.
THE
HIGH
SYSTEM PRESSURES COULD
BE
TRANS­
FERRED
INTO
THE
CHARGING
CAN
CAUSING
IT

TO EXPLODE.

(5) Screw
a can of R-12 to the
opened manifold
valve.
Be
sure gasket
is in
place
and in
good condi­
tion. Tighten refrigerant
can and
manifold locking nut
to
ensure
a
good seal.
Do not
overtighten.
Tighten
to 9.5 N*m (7 ft. lbs.)
torque,
if
gasket
is in
good condition.
(6) Turn manifold valve (above
the
refrigerant
can)

completely clockwise
to
puncture
the can.
This closes
the valve
and
seals
the
refrigerant
in the can.

CAUTION:
Do not
heat refrigerant
12
above
52°C

(125°F).

(7) Place refrigerant
can in a
large
pan of
water
heated
to
52°C (125°F). Place
pan of
water containing
the refrigerant
can on an
accurate scale
so the
amount
of
refrigerant added
can be
weighed. Open
the refrigerant manifold valve.
(8) Purge
all air
from test hoses.
Air in the
system
will
be
trapped
in the
condenser causing abnormally
high discharge pressures
and
interfering with con­ densing
of the
refrigerant.

HEATING
AND
AIR
CONDITIONING
24 - 29
CLIMATE CONTROL
SYSTEM

INDEX

page

Air Conditioner Distribution
and
Spot Cooler
Ducts-Center
. . 38

Air Conditioner Distribution
and
Spot Cooler
Ducts-Left Bi-Level
38

Air Conditioner Distribution
and
Spot Cooler

Ducts-Right
Bi-Level
38

Air
Outlet
Assemblies Right
Side
.............
38

Control Test
......
30
Defroster Duct
34

Electrical Controls
and
Circuits
30
Electronic Temperature Cycling Switch
37

Evaporator Control Unit
. . 34

GENERAL
INFORMATION
This
air
conditioner
is
designed specifically
for
con­
ventional
cab
trucks with
the
heater-evaporator
package designed
to fit
under
the
instrument panel.
The system
is
manually controlled
by the
operator. Controls have been kept simple
for
ease
of
service and operation. In
the
blend
air
reheat
air
conditioning unit,
all

the
air
entering
the
system passes through
the
evap­ orator.
A
selected portion passes through
the
heater
core depending
on the
position
of the
blend
air
door.
The system controls
are
located
in the
center
of the
instrument panel within easy reach
of the
driver.
The combination electrical
and
vacuum switch con­
trols
the
compressor clutch, mode
of
operation
and

blower. Modes
are Off, Max. A/C, A/C,
Vent, Heat and Defrost.
A
4-speed blower motor switch controls
the amount
of air
flow.
The
evaporator-heater pack­ age includes:
•
The
blower motor. • Intake duct with outside
air
recirculating door.
• Evaporator coil
• Heater core.
• Defroster discharge doors.
• Blower motor speed resistors.
• Vacuum harness.
• Vacuum actuators.
•
A/C air
outlets
to the
distribution ducts. Defrost, Heat,
A/C and
Vent modes automatically
supply
100%
outside
air.
The
air
distribution ducts supply
air
from
the
unit
to
4
panel mounted, fully directional, outlets.
The
faceplate
has 2
outlets
and 2 are
snapped into
the

panel
on the
right side. Satisfactory performance
of the air
conditioning
and heating system
is
dependent upon correct opera­
tion
and
adjustment
of all
operating controls.
The in­
spections, tests
and
adjustments should
be
used
to

locate
the
cause
of a
malfunction.
The
tests
in
this
page

Evaporator Heater Assembly
36

Expansion
(H)
Valve
37

Faceplate
32

General Information
. 29

Heater Assembly
. 33

Heater Control
32

Louver
Assemblies
39

Operation
of All
Controls
29
Resistor
Block
33

Temperature
and
Mode Control Cables
. 32
Vacuum
Actuators
36
Vacuum
Controls
and
Circuits
30

manual have been arranged
in a
logical sequence
that
has
proved
to be the
surest
and
shortest route
to
accurate diagnosis.
It is
recommended that they
be

followed
and
performed
in the
order they
are
pre­ sented.

OPERATION
OF ALL
CONTROLS
Operation must
be
tested
as
described
in the
fol­
lowing sequence: (1) Inspect, test,
and
adjust compressor drive belt.
(2) Start engine
and
adjust engine speed
to 1,300

RPM.
Use a
reliable tachometer. (3) Move temperature control lever
to
Cool position
and mode lever
to A/C
position. (4)
The
inlet
air
door should
be
open
to
outside
air.

Open vehicle windows. (5) Test
the
blower operation
at all 4
speed posi­

tions.
If the
blower does
not
operate correctly refer
to

Electrical Controls
and
Circuit. Leave
the
blower switch
in the
HIGH position.
(6)
The
compressor should
be
running
and the air

conditioning system
in
operation. In addition
to the six
position push button selector,
the
A/C
Heater control consists
of:
TEMPERATURE LEVER-Controls
the
tempera-.
ture
of the
discharge
air in all
modes except
MAX

A/C
and Off
when
the
vacuum operated water valve is closed. Moving
the
lever
to the
left provides cooler
air
and
moving
it to the
right provides warmer
air.
BLOWER SWITCH-The system blower
can be op­

erated
at 4
speeds.
•
LOW at the
bottom. • MEDIUM
1 at the
lower center.
• MEDIUM
2 at the
upper center.
• HIGH
at the top
switch position. The blower will
be on and
operating
at the
speed
selected,
in all
push button positions except
Off.
AIR DIRECTIONAL VANES-Air
is
delivered
through
4
panel outlets.
The 4
outlets
are
adjustable

•

Fig.
12
Blower
Wheel
(7) Install the 3 arms. Install nut that attaches 3
door arms to doors on the top cover of the unit (Fig.
11).

INSTALLATION
(1) Install the evaporator heater assembly. Plastic
instrument panel may have to be flexed outward.
(2) Install and tighten the screw that retains the
evaporator heater assembly to cowl side sheet metal.
(3) Install the retaining nuts on engine side.
(4) Connect vacuum lines on engine side.
(5) Install blower motor connector on engine side.
(6) Remove wiring connector from resistor block.
(7) Connect vacuum lines from extension on con­
trol unit and attach vacuum lines to defroster duct (Fig. 10).
(8) Connect temperature control cable to unit
through glove box. (9) Install floor air distribution duct.
(10) Install center distribution duct.
(11) Attach radio ground strap. (12) Remove right half of lower reinforcement by
removing screws attaching it to the instrument panel and the screw attaching it to the cowl side trim
panel. (13) Install ash receiver.
(14) Install structural brace through glove box
opening. Install screws and loosen nuts. (15) Install glove box by installing mounting
screws. (16) Install right cowl side trim panel, if so
equipped. (17) Position transfer case and/or gear shift levers.
(18) Remove plugs from heater hoses and unit. In­
stall condensate tube (Fig. 9). (19) Connect refrigerant and heater lines to unit
on engine side.
} (20) Connect the negative cable to the battery. (21) Fill the cooling system (refer to Group 7, Cool­
ing System). (22) Evacuate and charge the system.
(23) Check operation of all controls and perfor­
mance of the A/C system.
HEATING
AND AIR
CONDITIONING
24 - 37

'H"
VALVE

Fig.
13
Expansion
(H)
Valve
Assembly
ELECTRONIC
TEMPERATURE
CYCLING
SWITCH

REMOVAL
(1) Remove the electrical wires to the switch.
(2) Rotate switch counterclockwise to remove from
pressure switch port. (3) Remove and discard old O-ring.

INSTALLATION
(1) Install new O-ring. Refrigerant oil must be ap­
plied to the new O-ring.
(2) Rotate switch clockwise to install on suction
line pressure switch port. Tighten switch to 5.65 N#m (50 in. lbs.) torque.

CAUTION:
Power
tools
should
not be
used
for in­

stallation
of the switch. The
possibility
of stripping
the
switch
threads
occurs
above
5.88 N*m (52 in.
lbs.)
torque.
(3) Connect wires. (4) Verify operation.

EXPANSION
(H)
VALVE

REMOVAL
The system must be completely discharged before
opening any refrigerant lines. (1) Remove the bolt in center of plumbing sealing
plate (Fig. 13).
(2) Carefully pull refrigerant line assembly to­
wards front of vehicle. Take care NOT to scratch valve sealing surfaces with tube pilots.
(3) Remove the Torx Head screws (Fig. 13). Hold
valve, once cap screws are removed valve is com­
pletely disconnected.
(4) Carefully remove valve.