Operation CHARM: Car repair manuals for everyone.

Blower Power Transistor Test




Blower Power Transistor Test

1. Disconnect the 5P connector from the power transistor.

2. Measure the resistance between power transistor terminals No. 1 and No. 4. It should be about 1.4-1.5 kOhms.
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.





3. Carefully release the lock tab on terminal No. 3 (BLU/YEL) (A) in the 5P connector, then remove the terminal and insulate it from body ground.

4. Reconnect the 5P connector to the power transistor.

5. Supply 12 V to cavity No. 3 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.