Radiator Cooling Fan Motor Relay: Description and Operation

DESCRIPTION





Two relays control radiator fan operation. The radiator fan ON/OFF and the HALO relays are located in the Power Distribution Center (PDC). Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

OPERATION
The radiator fan ON/OFF relay energizes when the PCM provides a ground to the relay based on engine coolant temperature and air conditioning operation.
The radiator fan HI/LO relay operates in conjunction with the radiator ON/OFF relay. This relay switches fan speeds from LO to HI whenever engine coolant temperature reaches a specified temperature. LO speed fan control is provided by allowing current flow, from the ON/OFF relay, through the normally closed contacts in the HI/LO relay. For HI speed fan control, the PCM provides a ground to the coil side of the HI/LO relay.