Automatic Climate Controls

DESCRIPTION

The speed of the BLOWER MOTOR is determined by the voltage applied to the motor. At low blower speeds, the applied voltage is about 3 volts. As the voltage is increased, the blower speed increases until maximum blower speed is reached at battery voltage.

OPERATION

The speed at which the blower runs is determined by the HEATER AND A/C CONTROL ASSEMBLY from temperature signal inputs and the operating mode selected. The HEATER AND A/C CONTROL ASSEMBLY accepts input requests from the driver by the front panel push buttons.

The blower speed output from the HEATER AND A/C CONTROL ASSEMBLY is at Terminal K and is a voltage which changes in steps from minimum to maximum Blower Speed. There are six steps which are indicated by the six segment displays on the panel of the HEATER AND A/C CONTROL ASSEMBLY. At minimum blower speed, the output is 2 to 3 volts and at maximum blower speed it is 7 to 10 volts.

The output speed signal from Terminal K is an input to the BLOWER CONTROL MODULE at Terminal B of connector C2. An amplifier and driver circuit in the BLOWER CONTROL MODULE supplies voltage between 4.5 and 14.5 volts to the BLOWER MOTOR according to the input signal at Terminal B.

The voltage at the BLOWER MOTOR is fed back to the HEATER AND A/C CONTROL ASSEMBLY at Terminal L to allow precise speed control of the blower by the circuits in the HEATER AND A/C CONTROL ASSEMBLY.