When the ignition switch is in RUN, battery voltage is
supplied to the mode selector switch of the heater and A/C control . When
the mode selector switch is in any position but OFF, voltage is supplied
to the fan switch of the heater and A/C control.
The fan switch and the blower resistor assembly work together in order
to determine the amount of voltage that is supplied to the blower motor. The
blower motor is a DC motor whose speed is proportional to the input voltage.
With the blower switch in LO, the following actions occur:
| • | All 3 blower resistors are in the blower circuit. |
| • | The blower runs at the slowest speed. |
With the blower switch in M1, the following actions occur:
| • | The blower switch bypasses 1 resistor. |
| • | The blower runs faster. |
With the blower switch in M2, the following actions occur:
| • | The blower switch bypasses 2 resistors. |
| • | The blower runs even faster. |
With the blower switch in HI, the following actions occur:
| • | The blower switch bypasses the blower resistor. |
| • | The blower switch supplies voltage to the blower relay coil. |
| • | Battery voltage is supplied directly to the blower motor. |
| • | The blower runs at maximum speed. |
