Cooling System: Description and Operation

RADIATOR FAN

When the ignition switch is in the "ON" position, system voltage is applied through the IG Fuse to the FAN THERMOSTAT SWITCH. The FAN THERMOSTAT SWITCH closes when engine coolant temperature reaches 98°C (208°F). With the FAN THERMOSTAT SWITCH closed, voltage is applied to the coil side of the RADIATOR FAN RELAY. Since the RADIATOR FAN RELAY is permanently grounded at G101 (Hardtop) or G200 (Convertible), the contacts close and voltage is applied through Fusible Link B to the RADIATOR FAN MOTOR. The RADIATOR FAN MOTOR is permanently grounded at G102 (Hardtop) or G200 (Convertible) and will continue to operate as long as the FAN THERMOSTAT SWITCH remains closed.

When the engine temperature falls below 93°C (199°F), the FAN THERMOSTAT SWITCH opens, and voltage to the coil side of the RADIATOR FAN RELAY is interrupted, the contacts open and the RADIATOR FAN MOTOR stops.

A/C CONDENSER FAN

With the ignition switch in the "ON" position, system voltage is applied to the DUAL PRESSURE SWITCH through the IG Fuse. The DUAL PRESSURE SWITCH remains closed as long as refrigerant pressure is between 207 kPa (30 psi) and 2641 kPa (388 psi). With the DUAL PRESSURE SWITCH closed, voltage is applied to the coil side of the A/C (Compressor Clutch) Relay.

The A/C (Compressor Clutch) Relay is energized when the A/C AMPLIFIER grounds the coil of the relay. With the A/C (Compressor Clutch) Relay energized, voltage is applied through the A/C Fuse and the closed contacts of the A/C (Compressor Clutch) Relay to the coil of the A/C (Condenser Fan) Relay. Since the A/C (Condenser Fan) Relay is permanently grounded at G104, 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 G104, the fan operates as soon as voltage is applied.