180o Thermostat




To reduce the operating temptature and increase cooling potential install a 180 degree thermostat and MN12 Performance Cool Fan Switch.

Remove the old 197 degree thermostat.

Clean gasket surface and apply gasket maker Ford part # F7TZ-19554-AA and new gasket.

Apply sealant to surface and seat thermostat. Install the housing and tighten the two bolts to 15-22 lb-ft.


MN12 Performance Cool Fan Switch

The Cool Fan Switch is a bi-metal switch that controls the HIGH speed fan operation on all Ford EEC-IV and EEC-V cars where the computer controls fan operation. The sensor mounts to the surface of the radiator and is designed to turn the fan on at 200 degrees and off at 185 degrees.

The cooling fan motor is controlled during vehicle operation by the constant control relay module (CCRM) and powertrain control module (PCM), which will energize the cooling fan motor under the following conditions:

Cooling fan motor will run at low speed:

  • If engine temperature is higher than normal. Cooling fan motor starts running at 106 *C (222 *F) and stops running at 101 *C (214 *F).
  • If A / C is on and vehicle speed does not provide enough natural airflow. Cooling fan motor starts running at speeds at or below 69 km/ h (43 mph) and stops running at 77 km/ h (48 mph).

    • Cooling fan motor will run at high speed:

  • If engine temperature is higher than desirable and cooling fan motor has been operating at a low speed.
  • At 109 *C (228 *F) and stops running at 105 *C (220 *F).

    • The wide-open throttle (WOT) A/C cutout is used on supercharged engine applications. During hard acceleration, a signal is sent to the powertrain control module. The powertrain control module then signals the constant control relay module to cut off power to the A/C clutch field coil. This keeps the engine from being overloaded.
    MN12 Performance
    703-968-6513
    richt@mn12performance.com