Heater Unit/Core Replacement

SRS components are located in this area. Review the SRS component locations (see COMPONENT LOCATION INDEX ), and the precautions and procedures (see PRECAUTIONS AND PROCEDURES ) before doing repairs or service.

1. Do the 12 volt battery terminal disconnection procedure (see USING THE GR8 BATTERY DIAGNOSTIC STATION ).
2. Disconnect the A/C line from the evaporator core (see EVAPORATOR CORE REPLACEMENT ).
3. Drain the engine coolant from the radiator (see COOLANT CHECK ).
4. From the inlet heater hose, detach the clip (A). Slide the hose clamps (B) back, then disconnect the inlet heater hose (C) and the outlet heater hose (D) from the heater unit. Note the layout of the hoses.

   Engine coolant will run out when the hoses are disconnected; drain it into a clean drip pan. Be sure not to let coolant spill on the electrical parts or the painted surfaces. If any coolant spills, rinse it off immediately.

   Fig 1: Identifying Clip, Hose Clamps, Inlet Heater Hose And Outlet Heater Hose

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
5. Remove the mounting nut from the heater unit. Take care not to damage or bend the fuel lines or the brake lines, etc.
   Fig 2: Heater Unit Mounting Nut With Torque Specifications

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Remove the dashboard (see DASHBOARD/STEERING HANGER BEAM REMOVAL/INSTALLATION ).
7. Disconnect these connectors (A): The mode control motor, the power transistor, the evaporator temperature sensor, and the air mix control motor.
   Fig 3: Identifying Blower Motor Connectors And Wire Harness Clips

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Remove the duct (A) and the drain hose (B). Remove the mounting nuts and the blower-heater unit (C).
   Fig 4: Duct, Drain Hose, Mounting Nuts And Blower-Heater Unit With Torque Specifications

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
9. Remove the self-tapping screws and the heater core cover (A), the cap (B), and the grommet (C), and carefully pull out the heater core (D).
   Fig 5: Identifying Heater Core Cover, Cap, Grommet And Heater Core

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
10. Install the heater core and the evaporator core in the reverse order of removal.
11. Install the heater unit in the reverse order of removal, and note these items:
    • Do not interchange the inlet and outlet heater hoses, and install the hose clamps securely.
    • Refill the cooling system with engine coolant (see COOLANT CHECK ).
    • Make sure that there is no coolant leakage.
    • Make sure that there is no air leakage.
    • Refer to the evaporator core replacement (see EVAPORATOR CORE REPLACEMENT ).
12. Do the 12 volt battery terminal reconnection procedure (see RECONNECTION ).