Electric Cooling Fan

An electric, variable speed cooling fan is installed in a shroud attached to the rear of the radiator. The cooling fan is operated by a fan control module, integrated into the electric motor, under the control of the ECM via a PWM (Pulse Width Modulation) signal. An electrical connector at the right side of the shroud provides the interface between the cooling fan harness and the vehicle wiring.

The fan control module is provided with:

• A battery power supply from the EJB
• An ignition signal from the ECM relay in the EJB
• A PWM signal from the ECM
• A ground connection

The ECM varies the duty cycle of the PWM signal to the fan control module between 0 and 100% to operate the fan motor in one of four modes:

• Off
• Minimum speed - 750RPM
• Linear variable speed between minimum and maximum speeds
• Maximum speed - 2820RPM

  Under hot operating conditions, the electric cooling fan may continue to operate for up to 5 minutes after the engine has been switched off.

  The fan control module incorporates a temperature sensor to prevent damage caused by excessive heat at high ambient temperatures. Operation of the fan control module is discontinued if the temperature reaches 135 °C (275 °F). Operation resumes when the temperature decreases to 120 °C (248 °F).