Power Transistor HVAC: Service and Repair

Inspection

1. Ignition "ON"
2. Manually operate the control switch and measure the voltage of blower motor between pin 1 and 2.
3. Select the control switch to raise voltage until high speed.





Specification





*AUTO COOLING: Auto speed (4.5V~B+)
*AUTO HEATING: Auto speed (4.5V~10.5V)
4. If the measured voltage is not specification, substitute with a known-good power mosfet and check for proper operation.
5. If the problem is corrected, replace the power mosfet.

Replacement

1. Disconnect the negative (-) battery terminal.
2. Remove the crashpad lower panel.

3. Disconnect the power mosfet connector (A) at the connecting part between heater and blower unit.
4. Remove the power mosfet (B) after loosening the mounting screws.




5. Installation is the reverse order of removal.