Asked in
Heater Cores and Blower Fans

How do you replace a heater core in a 1979 f-250?


User Avatar
Wiki User
September 12, 2011 8:44PM
  1. Disconnect the negative battery cable
  2. Disconnect the temperature control and air door control cables from the heater housing.Carfully position the cables out of the way
  3. Disconnect the electrical wires from the blower resistor and the blower motor
  4. Remove the retaining screws holding the air inlet vent duct to the main body of the heater housing
  5. Disconnect the wires from the heater blower on the engine side of the firewall
  6. Drain the water from the radiator and remove the heater hoses from the heater core on the engine side of the firewall
  7. Remove the heater body retaining nuts from the studs on the engine side of the firewall
  8. Remove the heater assembly from the passanger side of the firewall
  9. Remove the gasket situated between the heater hose end and the dash panel where the core inlet and outlet tubes pass through
  10. Remove the heater core cover and gasket
  11. Pull the heater core and lower support from the main heater assembly