The compressor for the air conditioning (A/C) system is
driven by the engine through the following components:
| • | The A/C compressor clutch |
The A/C compressor will engage if the following conditions are met:
| • | A/C switch is not in the OFF position. |
| • | Outside temperature is above 6°C (43°F). |
| • | Refrigerant pressure is normal. |
| • | Engine speed does not exceed 5985 RPM. |
| • | Engine speed does not exceed 5325 RPM when A/C is previously requested
OFF. |
The electronic climate control (ECC) module serves as an interface between
the passenger and the A/C system. System voltage is supplied to the ECC module
by two sources:
| • | Continuous battery voltage source: |
| • | Interrupted battery voltage source: |
The ground path is provided by CKT 1850 (BLK) to grounds G203/G204.
The A/C request signal is generated by the ECC module. The ECC module
can produce the A/C request signal in two modes:
The A/C request signal produced by the ECC module has the following
route:
| • | CKT 203 (LT BLU) to the A/C compressor high pressure
cutoff switch |
| • | The A/C compressor high pressure cutoff switch to CKT 762
(DK GRN/WHT) to the VCM |
Along with the request signal, the VCM will monitor the system for high
and low pressure conditions.
The A/C System pressure data to the VCM is provided by the following
components:
| • | A/C compressor cycling switch and CKT 603 (DK GRN)
for low pressure |
| • | A/C compressor high pressure cutoff switch and CKT 762
(DK GRN/WHT) for high pressure |
The VCM supplies the ground path for the A/C compressor clutch relay
coil and CKT 459 (DK GRN/WHT). Voltage is provided by the IGN-E
fuse. With the relay energized the contacts will close and complete the
current path for the A/C compressor clutch.
The current path is provided by the following components:
| • | A/C compressor clutch relay |
The A/C compressor clutch diode is connected across the A/C compressor
clutch coil for circuit protection.
