Automatic Temperature Control

• Description
• Operation
  • Notes
  • Off
  • Vent
  • Lo
  • Auto
  • Hi
  • Bi-Level
  • Def
• System Response
• Control System Components
  • Temperature Dial
  • Circuit Board Electrical Switch
  • In-Car Turn-On Switch
  • Control Vacuum Switch
  • Sensors
    • In-Car Sensor
    • Ambient Sensor
  • Aspirator
  • Programmer
    • Notes
    • Amplifier
    • Transducer
    • Vacuum Motor
    • Blower Circuit Board Switch
    • Vacuum Valve
    • Feedback Potentiometer
    • Vacuum Checking Relay
    • Air-Mix Door Link
  • Heater Turn-On Switch
  • Heater Water Valve
• Summary Of ATC System Operation
  • Notes
  • Temperature Control
    • Notes
    • Input
    • Output
  • Blower Control
    • Notes
    • Blower Turn-On
  • Auxiliary Electrical & Vacuum Functions
    • Electrical
    • Vacuum
• Adjustments
• Problem Diagnosis & Troubleshooting
  • Notes
  • Def - Dial @ 85
  • Bi-Level - Dial @ 75
  • Hi - Dial @ 65
  • Auto - Dial @ 65
  • Auto - Dial @ 85
  • Lo - Dial @ 85
  • Vent - Dial @ 85
  • Off - Dial @ 65
  • Temperature Control Diagnosis
    • System Operates Only At Maximum Air Conditioning
    • System Operates Only At Maximum Heating
    • SYSTEM FLUCTUATES BLOWER SPEEDS and/or MODE SHIFTS DURING ACCELERATION
    • Dial Setting Does Not Provide Comfort
    • Blower Cycling And Mode Cycling
    • Insufficient Heating Or Cooling
  • Blower Circuit Control Diagnosis
    • No Blower In Off. Vent Or LP Settings
    • Operates At Low Blower Only Except In "Hi" And "Def"
    • Blower Operation Only In "Hi" Or "Def"
    • Blower Speed Varies In "Hi" And "Def"
    • Blower Operates With Ignition Off
    • Blower Speeds Skipped In "Auto" Setting
    • No Heater Turn-On In Cold Weather Except In "Vent" And "Def"
    • Immediate Heater Turn-On In Cold Weather
    • A/C Delayed In Hot Weather Until Engine Warms Up (Unless Control Lever Is In "Vent" Or "Def"
    • System Operates Only At Low Blower
    • No Blower Operation In Any Lever Setting
  • Auxiliary Vacuum Problem Diagnosis
    • Upper And Lower Mode Door Actuation Problems
    • Defroster Bleed Problems
    • Defroster Door Actuation Problems
    • RECIRC Air Door Actuation Problems
    • Heater Water Valve Control Problems
    • Auxiliary Vacuum Circuit Check Valve Problems
    • Compressor Electrical Problems
• Auxiliary Vacuum Circuit Test Procedure
  • Notes
  • Refrigeration Problem Diagnosis
  • Low Refrigerant Detection System
  • Capacity Performance Test & Diagnosis
• System Testing
• Refrigeration Diagnosis Chart
• Refrigeration Diagnosis Chart - VIR Valves-In-Receiver System