Q: How to remove and install a heater core in Ford F-250 non-air conditioned models?
A: Disconnect negative battery terminal cable. Disconnect temperature control cable from temperature blend door and mounting bracket. Disconnect wires from Blower Motor Resistor and blower motor. Drain coolant from Radiator. Disconnect heater hoses from heater core tubes. Remove nuts retaining heater case and plenum to dash panel. Remove screw retaining heater case to dash panel. Remove screws retaining heater case to dash panel. Remove heater case assembly. Remove heater housing plate. Remove heater core and seal. Installation: Reverse removal steps. Slide self-adjusting clip on temperature control cable. Snap temperature control cable onto cable mounting bracket. Adjust temperature control cable. Fill radiator with coolant. Attach cable to negative battery terminal. Check for leaks. All other models (cab-mounted heater cores) Removal: Disconnect negative battery terminal cable. Drain coolant from radiator. Disconnect heater hoses from heater core. Remove glove box. Remove screws attaching heater core cover to plenum assembly. Disconnect vacuum source. Remove cover. Remove heater core from plenum chamber. Installation: Reverse removal steps. Fill radiator with coolant. Check for leaks.