Power Mosfet

Inspection

1. Disconnect the negative (-) battery terminal.
2. Remove the power mosfet. Measure resistance between Drain and Source using resistance tester. You can estimate whether power mosfet is failure or not refering to the specification.






FET Fail Check






3. If If the measured resistance is not normal specification, replace the power mosfet.
4. If it is normal, install the power mosfet and ignition "ON".
Manually operate the control switch and measure the voltage between pin 1 and 2 of blower motor.
5. Select the control switch to raise voltage until high speed.










6. If the measured voltage is not within specification, substitute with a known-good power mosfet and check for proper operation.
7. If the problem is corrected, replace the power mosfet.