Diesel Data: Automotive Repair

Front Power Transistor Test




Front Power Transistor Test

1. Remove the passenger's dashboard undercover Passenger's Dashboard Undercover Removal/Installation.

2. Disconnect the 4P connector from the front power transistor.

3. Measure the resistance between terminals No. 3 and No. 4 of the front power transistor. It should be about 1.5 kOhms.

- If the resistance is within the specifications, go to step 4.
- If the resistance is not within the specifications, replace the front power transistor.
NOTE: Also check the front blower motor. Front power transistor failure can be caused by a defective front blower motor.





4. Reconnect the 4P connector to the front power transistor.

5. Disconnect HVAC control unit connector B (16P).

6. Connect HVAC control unit connector B (16P) terminals No. 13 and No. 15 with a jumper wire.






7. Turn the ignition switch to ON (II), and check that the front blower motor runs.

- If the front blower motor does not run, replace the front power transistor.
NOTE: A faulty front blower motor can cause the front power transistor to fail. Before replacing the front power transistor, check the front blower motor for binding, and replace it if necessary.
- If the front blower motor runs, the front power transistor is OK.