Blower and A/C Controls (Auto)
Auto A/C control module controls the blower motor speed by shifting the base voltage of power transistor.
Power Transistor
1. Measure voltage between pin 1 and pin 2.
2. The voltage increases up to selecting blower motor speed button until Hi-blower relay works.
Heater, Blower and Evaporator
1. Check the link mechanism for operation.
2. Check the heater core for restriction or water linkage.
3. Check the water valve for operation and clogging.