Radiator Cooling Fan Motor Relay: Description and Operation

RADIATOR FAN ON RELAY - PCM OUTPUT
The relay is located in the PDC. The inside top of the PDC cover has label showing relay and fuse identification.

The radiator fan ON relay energizes when the PCM provides a ground to the relay. The radiator fan relay is located below the heater blower motor housing. The PCM grounds the radiator fan relay when engine coolant exceeds 97 °C (207 °F). The PCM turns the fan off when coolant temperature drops to 94 °C (201 °F). Also, the PCM energizes the ON relay whenever the A/C system operates. Refer to Radiator Fan LOW/HIGH Relay for fan operation.

RADIATOR FAN LOW/HIGH RELAY - PCM OUTPUT
The relay is located in the PDC. The inside top of the PDC cover has label showing relay and fuse identification.

The radiator fan LOW/HIGH relay works in conjunction with the radiator fan ON relay. If the coolant temperature is below 102 °C (216 °F), the current flow for the fan is through the normally closed contacts of the LOW/HIGH relay. If the coolant temperature is above 102 °C (216 °F) LOW/HIGH relay and the radiator fan changes to high speed. The PCM turns OFF high speed fan operation when coolant temperature drops to 102 °C (216 °F). The low speed will continue until temperature drops below 94 °C (201 °F). Cooling fan turns OFF at 77 mph, when accelerating, and turns back ON at 67 mph.