Circuit Operation
ENGINE COOLING FANWhen the Ignition Switch is in the "ON" position, system voltage is applied through the IG-COIL Fuse (in Junction Block) to the Engine Cooling Fan Relay (RDTR). The Powertrain Control Module (PCM) will apply ground to the coil side of the RDTR when it senses high engine coolant temperature 98°C (208°F) from the Engine Coolant Temperature (ECT) Sensor With power and ground applied to the coil of the RDTR, the contacts close and voltage is applied through the RDTR Fuse to the Engine Cooling Fan Motor. The Engine Cooling 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 PCM will interrupt ground to the coil side of the RDTR, the contacts open and the Engine Cooling Fan Motor stops.
A/C CONDENSER FAN
With the Ignition Switch in the "ON" position, system voltage is applied to the A/C 1 Relay (Compressor Clutch) through the HEATER Fuse. The A/C 1 Relay (Compressor Clutch) is energized when the A/C Amplifier grounds the coil of the relay. With the A/C 1 Relay (Compressor Clutch) energized, voltage is applied through the A/C Fuse and the closed contacts of the A/C 1 Relay (Compressor Clutch) to the coil of the A/C 2 Relay (Condenser Fan). Since the A/C 2 Relay (Condenser Fan) is permanently grounded at G102, the relay energizes, the contacts close, and voltage is applied to the A/C Condenser Fan Motor. Because the A/C Condenser Fan Motor is permanently grounded at G103, the coolant fan operates as soon as voltage is applied.