Section 12-00: Climate Control System, Service
1996 F-150, F-250, F-350, F-Super Duty and Bronco, F-Super Duty Motorhome Chassis Workshop Manual
DIAGNOSIS AND TESTING

Symptom Chart — Climate Control System

CLIMATE CONTROL SYSTEM
ConditionPossible SourceAction
  • Insufficient, Erratic, or No Heat
  • Low radiator coolant due to coolant leaks.
  • CHECK radiator cap pressure. REPLACE if below minimum pressure. FILL to specified coolant level. PRESSURE TEST for engine cooling system and heating system leaks. SERVICE as required.
 
  • Engine overheating.
  • REMOVE bugs, leaves, etc. from radiator and support or A/C condenser core fins. CHECK for:
      Operation of engine fan clutchLoose drive beltSticking thermostatIncorrect ignition timingWater pump impeller damageRestricted cooling system
    • SERVICE as required.
 
  • Loose drive belt.
  • REPLACE drive belt if cracked or worn and ADJUST drive belt tension.
 
  • Thermostat.
  • FEEL heater water hoses. If the heater water hoses are too hot to hold, the thermostat is OK. If the heater water hoses do not get too hot to hold, REPLACE the thermostat. If only one heater water hose gets hot while the other remains cool, a plugged heater water hose or heater core is indicated.
 
  • Heater water hoses.
  • Blower Motor Does Not Operate Properly
  • Blower motor.
  • Insufficient Cooling
  • Low refrigerant charge.
  • No Switching Between Function Selections
  • Vacuum leak.