Engine Cooling Fan: Operation

Cooling fan is controlled by the Integrated Relay Controller Module (IRCM) and Electronic Engine Control (EEC-IV) module. The modules energize cooling fan under the following conditions:

• Engine temperature is above normal. Low-speed fan runs at 222°F (106°C) and goes off at 214°F (101°C) on Thunderbird.
• Engine temperature is above normal. Low-speed fan runs at 215°F (102°C) and goes off at 210°F (99°C) on Continental, Taurus and Sable.
• A/C is on and vehicle speed is less than 43 MPH.
• Cooling fan is turned on high speed if engine temperature is higher than desirable and fan has been operating at a low speed. Fan runs at 230°F (110°C) and goes off at 224°F (107°C). On Continental, cooling fan will operate at high speed when coolant temperature reaches 236°F (113°F) with engine idling.

  During hard acceleration, the Wide Open Throttle A/C Cut-Off (WAC) relay controls the A/C. A signal is sent to EEC-IV and then to the IRCM, where the module de-energizes the A/C clutch, decreasing engine load during acceleration.

  Several different controllers are available depending on application. Proper operation of the system cannot be obtained unless proper controller is used.