Condenser Fan Control

The [1][2]condenser fan ensures a sufficient amount of airflow across the condenser throughout the vehicle's operating range. Ignition voltage is applied to the coil side of the condenser fan relay through the DEF fuse. Battery voltage is applied to the switch side of the condenser fan relay through the HTR fuse. When the relay is energized, battery voltage is applied to the A/C condenser fan through the A/C fuse and the closed contacts of the relay. Since the A/C condenser fan is grounded at G105, the condenser fan operates as long as the relay is energized. The PCM will ground the condenser fan relay coil under any of the following conditions:
^ The A/C system is operating.
^ The ECT is 110°C (230°F) or higher indicating an overheating condition.
^ The PCM detects an ECT sensor malfunction.

The PCM monitors Engine Coolant Temperature (ECT). If the ECT rises above 110°C (230°F), indicating an overheating condition, the PCM sends a cut out signal to the A/C compressor control module, prompting the A/C compressor control module to disengage the A/C compressor clutch in order to reduce engine load. The PCM sends a cut out signal to the A/C compressor control module under any one of the following conditions:
^ The ECT is 110°C (230°F) or higher.
^ After opening the throttle valve 71 degrees or more.
^ When the engine speed is less than 500 RPM, or greater than 6500 RPM.
^ The A/C compressor control module signal is absent.