No Blower Motor Control

1. Defective blower motor resistor.
2. Defective blower switch.
3. Defective in car and/or ambient sensors.
4. Defective rheostat.
5. Defective power servo unit.
6. Defective double vacuum valve.
7. Defective warm up relay.
8. Defective amplifier.
9. Defective heater mode switch.
10. Defective coolant temperature switch.
11. Defective wiring or ground connections.
12. Defective vacuum circuit.