Radiator Cooling Fan Relay

An electric radiator cooling fan is used on 4.0L models with A/C and/or heavy-duty cooling. PCM operates cooling fan, regardless of temperature, whenever A/C compressor clutch is activated. Normal operation of the radiator cooling fan is controlled by PCM through ECT sensor input.

When engine coolant temperature reaches 217°F (103°C), PCM supplies radiator cooling fan relay with a ground path. Radiator cooling fan relay contacts close and allow battery voltage from ignition switch to reach radiator cooling fan motor. When coolant temperature drops to 208°F (98°C), PCM will remove radiator cooling fan relay ground path.