Circuit/System Description
WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.
When the A/C switch is pressed or defrost mode is selected with the blower on and system conditions are such that A/C operation is allowed, the ECM will apply ground through the A/C compressor clutch relay control circuit, energizing the A/C compressor clutch relay. With the relay energized, battery voltage is applied through the control circuit to the A/C compressor clutch assembly, engaging the A/C compressor.