Cooling System: Description and Operation

When the engine coolant temperature reaches 207°F, the engine coolant temperature switch closes and grounds the coil, energizing the cooling fan relay. The cooling fan relay contacts close and voltage is supplied to the engine cooling fan motor. The cooling fan motor will operate the coolant temperature drops below 194°F.

The engine cooling fan motor will also operate when the ECM senses A/C system operation. This reduces coolant temperature in compensation for the additional load from the A/C system.