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 two sources.
Continuous battery voltage source:
| • | RDO BATT fuse 19. |
| • | CKT 340 (ORN). |
Interrupted battery voltage source:
| • | Ignition switch (RUN position). |
| • | HVAC I fuse 21. |
| • | CKT 341 (BRN). |
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 can produce the blower motor speed signal in two modes of operation:
| • | Automatic operation. |
| • | Manual operation. |
In the manual operation mode thirteen speed settings are available and, once selected, 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 to maintain customer selected temperature.
The blower motor speed signal produced by the ECC module has the following route:
- ECC module to CKT 760 (PPL/WHT).
- CKT 760 (PPL/WHT) to the blower motor.
Battery voltage for the blower motor is provided by the following components:
- The HVAC fuse.
- CKT 540 (ORN).
The ground path is provided by CKT 850 (BLK) to ground G117.
