Radiator Cooling Fan Motor Relay: Description and Operation

PURPOSE
A signal from the ECU controls the radiator fan relay and thus the radiator cooling fan. The ECU calculates inputs from the coolant temperature sensor and vehicle speed sensor to determine when to energize the fan relay. The A/C switch is an added input on models so equipped. The ECU simultaneously turns "ON" or "OFF" the main radiator fan and A/C auxiliary fan as well as setting them at "HI" or "LO" speed.