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Power Transistor Test

  1. Disconnect the 5P connector from the power transistor.
  2. Measure the resistance between the No. 1 and No. 4 terminals of the power transistor. It should be about 1.4-1.5 kΩ.
    NOTE: Also check the blower motor. Power transistor failure can be caused by a defective blower motor.
    • If the resistance is within the specifications, go to step  3.
    • If the resistance is not within the specifications, replace the power transistor.
    Fig 1: Measuring Resistance Between Terminals Of Power Transistor
    G05115918Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Carefully release the lock tab on the No. 3 terminal (BLU/YEL) (A) in the 5P connector, then remove the terminal and insulate it from body ground.
    Fig 2: Removing Terminal And Body Ground
    G05115919Courtesy of AMERICAN HONDA MOTOR CO., INC.
  4. Reconnect the 5P connector to the power transistor.
  5. Supply 12 V to the No. 3 cavity with a jumper wire.
  6. Turn the ignition switch to ON (II), and check that the blower motor runs.
    • If the blower motor does not run, replace the power transistor.
      NOTE: A faulty blower motor can cause the power transistor to fail. If the power transistor is replaced, also check the blower motor for binding, and replace it if necessary.
    • If the blower motor runs, the power transistor is OK.