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 battery terminal disconnection procedure (see BATTERY TERMINAL DISCONNECTION AND RECONNECTION ).
2. Recover the refrigerant with a recovery/recycling/charging station (see REFRIGERANT RECOVERY  ).
3. Disconnect the A/C line from the evaporator core (see EVAPORATOR CORE REPLACEMENT  ).
4. When the engine is cool, drain the engine coolant from the radiator (see COOLANT CHECK ).
5. From under the hood, slide the hose clamps (A) back. Disconnect the inlet heater hose (B) and the outlet heater hose (C) 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: Locating Hose Clamps, Inlet Heater Hose And Outlet Heater Hose

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

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Remove the dashboard (see DASHBOARD/STEERING HANGER BEAM REMOVAL/INSTALLATION ).
8. Disconnect the connector (A). Remove the clips (B), ducts (C), and the drain hose (D). Then remove the mounting nuts, and the blower-heater unit (E).
   Fig 3: Locating Connector, Clips, Ducts And Drain Hose With Torque Specifications

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
9. Disconnect the connector (A) from the blower motor, and detach the wire harness clip (B).
   Fig 4: Locating Blower Motor Connector And Wire Harness Clip

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
10. Disconnect these connectors (A): The mode control motor, the power transistor, the evaporator temperature sensor, the passenger's air mix control motor, and the recirculation control motor. Remove the wire harness clips (B).
    Fig 5: Locating Mode Control Motor Connector, Power Transistor Connectors And Wire Harness Clips

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. Disconnect the connector (A) from the driver's air mix control motor. Remove the wire harness clips (B), the connector clip (C), and the wire harness (D).
    Fig 6: Locating Wire Harness Clips, Connector Clip And Wire Harness

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
12. Remove the passenger's air mix control motor (see PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT  ).
13. Remove the self-tapping screws and the passenger's heater duct (A). Remove the self-tapping screws and the expansion valve cover (B). Remove the self-tapping screw and the heater core cover (C). Remove the self-tapping screws, the heater pipe bracket (D), and the grommet (E), and carefully pull out the heater core (F).
    Fig 7: Locating Expansion Valve Cover, Heater Core Cover, Heater Pipe Bracket And Heater Core

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
14. Install the heater core and the evaporator core in the reverse order of removal.
15. 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.
16. Do the battery terminal reconnection procedure (see BATTERY TERMINAL DISCONNECTION AND RECONNECTION ).