Power Transistor HVAC: Testing and Inspection

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.