Chevrolet 1980 Light Duty Truck Service Manual page 47

Chevrolet vehicles equipped with a catalytic converter, it will be
necessary to warm the engine to a normal operating temperature before
attempting to idle the engine for periods greater than five (5) minutes.
Once the choke is open and fast idle speed reduced to a normal idle,
diagnosis and adjustments can be made.
General Description.......................................................IB-1
C60 System (C-K & G M odels)................................IB-1
Overhead Systems (C-K-G M odels)........................ .IB-1
Motor Home Chassis System......................................IB-1
System Control.............................................................IB-5
Diagnosis....................................................................... .IB -11
Leak Testing The Refrigerant System..................... .IB -12
Pressure Cycling System Diagnosis......................... .1B -15
Compressor Diagnosis............................................... .1B-15
Insufficient Cooling......................................................IB -15
Electrical System Diagnosis ...................................... .IB -19
Evacuating and Charging Procedures........................ .IB-26
Air Conditioning System Capacity.......................... .IB-26
Checking O il............................................................... .IB-27
On Vehicle Service..........................................................IB-26
Engine Idle Compensator.......................................... ..IB-32
Compressor.................................................................. ..IB-32
C60 System-C-K Models.......................................... .IB-34
Condenser.................................................................... .IB-34
Accumulator-All........................................................IB-34
Blower Assembly........................................................IB-34
Evaporator Core..........................................................IB-35
Expansion Tube-All................................................. .IB-35
Selector Duct and Heater Core................................IB-35
Kick Panel Air Valve.............................................. .IB-35
Plenum Air Valve......................................................IB-35
Control Assembly.............................. .......................IB-35
Temperature Door Cable Adjustment..................IB-35
Master Switch and/or Blower Switch....................IB-35
Vacuum Tank.............................................................IB-37
Blower Resistor U nit............................................... .IB-37
Blower Motor R elay............................................... .IB-37
Fuse...............................................................................IB-37
Overhead System-C-K Models....... ..........................IB-38
Rear Duct.................................................................... .IB-38
Blower Motor Resistor.............................................. .IB-38
Blower Motor Assembly............................................ .IB-38
Expansion Valve.........................................................IB-40
Evaporator Core....................................................... ..IB-41
Blower Motor Switch............................................... ..IB-41
SECTION 1 B
AIR CONDITIONING
NOTICE: When performing air conditioning diagnosis on
CONTENTS
AIR CO N D ITIO N IN G
F use.............................................................................IB-42
C60 System-G Models.............................................. .IB-42
Condenser.................................................................. .IB-42
A/C Air Distributor D u ct........................................1B-42
A/C Center and Right Dash Outlets,
Heater, Air Distributor and Extension Ducts.... ..IB-42
Heater Core Case and Core......................................1 B-42
Expansion Valve..........................................................IB-43
Blower Motor..............................................................IB-43
Evaporator Core.........................................................IB-44
Temperature Door Cable......................................... .IB-44
Control.........................................................................IB-44
Blower Switch........................................................... .IB-44
Blower Motor Relay................................................ .IB-44
Resistors.................................................................... ..1 B-,44
Blower Motor Relay................................................ .IB-45
Pressure Cycling Switch.......................................... .IB-47
Vacuum Tank............................................................ ..IB-47
Circuit Breaker............................................................IB-47
Overhead System-G Models.......................................IB-47
Dash Mounted System-Motor Home U nits.......... ..IB-52
Condenser.................................................................. ..IB-52
Receiver-Dehydrator................................................ ..IB-52
Sight G lass................................................................ .IB-53
Blower-Evaporator Assembly...................................IB-53
Blower Assembly.......................................................IB-53
Expansion Valve, Evaporator Case or Core......... .IB-53
Thermostatic and/or Blower Switches................... .IB-53
Resistor.........................................................................IB-54
Fuse..............................................................................IB-54
Specifications...............................................................IB-56
Special Tools.............................................................. ..IB-57
1B-1
L IG H T T R U C K SER V IC E M ANUAL