Chrysler DODGE D150 1993 Service Manual page 1466

HEATING AND AIR CONDITIONING 24 - 29
CLIMATE C O N T R O L SYSTEM
INDEX
page
Air Conditioner Distribution and Spot Cooler
D u c t s - C e n t e r . . 3 8
Air Conditioner Distribution and Spot Cooler
Ducts-Left Bi-Level 38
Air Conditioner Distribution and Spot Cooler
D u c t s - R i g h t Bi-Level 3 8
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 t h e 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 t h e 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 h a s 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 3 6
Expansion (H) Valve 37
Faceplate 3 2
General Information . 2 9
Heater Assembly . 3 3
Heater Control 3 2
Louver Assemblies 3 9
Operation of All Controls 2 9
Resistor Block 3 3
Temperature and Mode Control Cables . 3 2
Vacuum Actuators 3 6
Vacuum Controls and Circuits 30
manual have been arranged in a logical sequence
t h a t has proved to be the surest and shortest route to
accurate diagnosis. It is recommended that they be
followed and performed in t h e 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 a t all 4 speed posi­
tions. If t h e blower does not operate correctly refer to
Electrical Controls and Circuit. Leave the blower
switch in t h e HIGH position.
(6) The compressor should be running and the air
conditioning system in operation.
In addition to t h e six position push button selector,
the A/C Heater control consists of:
TEMPERATURE L E V E R - C o n t r o l s the tempera-.
ture of t h e discharge air in all modes except MAX
A/C and Off when t h e vacuum operated water valve
is closed. Moving t h e lever to the left provides cooler
air and moving it to the right provides warmer air.
BLOWER S W I T C H - T h e system blower can be op­
erated at 4 speeds.
• LOW a t the bottom.
• MEDIUM 1 a t t h e lower center.
• MEDIUM 2 at t h e upper center.
• HIGH a t the top switch position.
The blower will be on and operating a t the speed
selected, in all push button positions except Off.
AIR DIRECTIONAL V A N E S - A i r is delivered
through 4 panel outlets. The 4 outlets are adjustable