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Blower Motor Circuit Troubleshooting

  1. Turn the ignition switch to ON (II) and the heater fan switch ON.

    Does the blower motor run in each speed? 

    YES  - Go to step  2.

    NO  - Go to step  16.

  2. Turn the heater fan switch OFF.
  3. Make sure the ignition switch is ON (II).

    Does the blower motor run? 

    YES  - Go to step  4.

    NO  - Go to step  9.

  4. Turn the ignition switch to LOCK (0).
  5. Disconnect the blower motor 2P connector.
  6. Disconnect the blower resistor 4P connector.
  7. Disconnect the heater fan switch 7P connector.
  8. Check for continuity between the No. 1, 2, 4, and 5 terminals of the heater fan switch 7P connector and body ground individually.
    Fig 1: Checking Continuity Between Terminals Of Heater Fan Switch 7P Connector And Body Ground
    G05456434Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short to body ground in the wires between the blower motor, the blower resistor and the heater fan switch.

    NO  - Replace the heater fan switch.

  9. Turn the ignition switch to LOCK (0).
  10. Disconnect the blower resistor 4P connector.
  11. Test the blower resistor (see BLOWER RESISTOR TEST ).

    Is the blower resistor OK? 

    YES  - Go to step  12.

    NO  - Replace the blower resistor.

  12. Reconnect the blower resistor 4P connector.
  13. Disconnect the heater fan switch 7P connector.
  14. Turn the ignition switch to ON (II).
  15. Ground each of the heater fan switch 7P connector terminals individually in the following order: No. 1,2, 4, and 5.
    Fig 2: Connecting Heater Fan Switch 7P Connector Terminals To Ground
    G05456435Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Does the blower motor run at progressively higher speeds? 

    YES  - Replace the heater fan switch.

    NO  - Repair any open or cause of excessive resistance in the appropriate wires between the blower resistor and the heater fan switch.

  16. Turn the heater fan switch OFF and the ignition switch to LOCK (0).
  17. Check the No. 5(40 A) fuse in the under-hood fuse/relay box, and the No. 10 (7.5 A) fuse in the under-dash fuse/relay box.

    Are the fuses OK? 

    YES  - Go to step  18.

    NO  - Replace the fuses, and recheck. If the fuses blow again, check for a short in the No. 5 (40 A) and No. 10 (7.5 A) fuses circuit.

  18. Connect the No. 2 terminal of the blower motor 2P connector to body ground with a jumper wire.
    Fig 3: Connecting No. 2 Terminal Of Blower Motor 2P Connector To Body Ground With Jumper Wire
    G05456436Courtesy of AMERICAN HONDA MOTOR CO., INC.
  19. Turn the ignition switch to ON (II).

    Does the blower motor run? 

    YES  - Go to step  20.

    NO  - Go to step  27.

  20. Turn the ignition switch to LOCK (0).
  21. Disconnect the jumper wire.
  22. Disconnect the heater fan switch 7P connector.
  23. Connect the No. 5 terminal of the heater fan switch 7P connector to body ground with a jumper wire.
    Fig 4: Connecting No. 5 Terminal Of Heater Fan Switch 7P Connector To Body Ground With Jumper Wire
    G05456437Courtesy of AMERICAN HONDA MOTOR CO., INC.
  24. Turn the ignition switch ON (II).

    Does the blower motor run? 

    YES  - Go to step  25.

    NO  - Repair open in the wire between the blower motor and the heater fan switch.

  25. Turn the ignition switch to LOCK (0).
  26. Check for continuity between the No. 3 terminal of the heater fan switch 7P connector and body ground.
    Fig 5: Checking Continuity Between No. 3 Terminal Of Heater Fan Switch 7P Connector And Body Ground
    G05456438Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Replace the heater fan switch.

    NO  - Check for an open in the wire between the heater fan switch and body ground. If the wire is OK, check for poor ground at G403 (see GROUND TO COMPONENTS INDEX ).

  27. Disconnect the jumper wire.
  28. Disconnect the blower motor 2P connector.
  29. Measure the voltage between the No. 1 terminal of the blower motor 2P connector and body ground.
    Fig 6: Measuring Voltage Between No. 1 Terminal Of Blower Motor 2P Connector And Body Ground
    G05456439Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Replace the blower motor.

    NO  - Go to step  30.

  30. Turn the ignition switch to LOCK (0).
  31. Remove the blower motor relay from the under-dash fuse/relay box, and test it (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  - Go to step  32.

    NO  - Replace the blower motor relay.

  32. Measure the voltage between the No. 1 terminal of the blower motor relay 4P socket and body ground.
    Fig 7: Measuring Voltage Between No. 1 Terminal Of Blower Motor Relay 4P Socket And Body Ground
    G05456440Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  33.

    NO  - Repair open in the wire between the No. 5 (40 A) fuse in the under-hood fuse/relay box and the blower motor relay.

  33. Turn the ignition switch to ON (II).
  34. Measure the voltage between the No. 3 terminal of the blower motor relay 4P socket and body ground.
    Fig 8: Measuring Voltage Between No. 3 Terminal Of Blower Motor Relay 4P Socket And Body Ground
    G05456441Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  35.

    NO  - Repair open in the wire between the No. 10 (7.5 A) fuse in the under-dash fuse/relay box and the blower motor relay.

  35. Turn the ignition switch to LOCK (0).
  36. Check for continuity between the No. 4 terminal of the blower motor relay 4P socket and body ground.
    Fig 9: Checking Continuity Between No. 4 Terminal Of Blower Motor Relay 4P Socket And Body Ground
    G05456442Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair open in the BLU/WHT wire between the blower motor relay and the blower motor.

    NO  - Check for an open in the wire between the blower motor relay and body ground. If the wire is OK, check for poor ground at G402 (see GROUND TO COMPONENTS INDEX ).

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