The electronic climate control (ECC) module serves as an interface between the passenger and the blower motor. System voltage is supplied to the ECC module by the following sources:

The ground path is provided by CKT 1050 (BLK) to grounds G203/G204.

The ECC module determines the appropriate blower motor speed and sends a pulse width modulated (PWM) signal to the blower motor. The ECC module may produce the blower motor speed signal in two modes of operation:

In the manual operation mode 13 speed settings are available and, once selected, the fan speed remains constant until a new speed is selected. In the automatic operation mode the ECC module will determine what blower speed is necessary in order to maintain customer selected temperature.

The blower motor speed signal produced by the ECC module has the following route:

1. ECC module to CKT 760 (PPL/WHT)
2. CKT 760 (PPL/WHT) to the blower motor

Battery voltage for the blower motor is provided by the following components:

The ground path is provided by CKT 850 (BLK) to ground G117.