Radiator Fan

When the Ignition Switch is in the "ON" position, system voltage is applied through the IG Fuse (in Junction Block) to the RDTR Relay. The Engine Control Module (ECM) will apply ground to the coil side of the RDTR FAN Relay when it senses high engine coolant temperature (98°C/2O8°F) from the Engine Coolant Temperature (ECT) Sensor. With power and ground applied to the coil of the RDTR FAN Relay, the contacts close and voltage is applied through the RDTR Fuse to the Radiator Fan Motor. The Radiator Fan Motor is permanently grounded at G102 and will continue to operate until the engine coolant temperature falls below 93°C (199°F).

When the engine coolant temperature falls below 93°C (199°F), the ECM will interrupt ground to the coil side of the RDTR Fan Relay, the contacts open and the Radiator Fan Motor stops.