Radiator Fan Relay

Power Distribution Center Location:

LOCATION

Relay is located inside the power distribution center (next to the battery).


PURPOSE

Relay supplies battery voltage to radiator fans.


OPERATION

The cooling system uses two fans. Both fans operate at two differant speeds, low and high. Depending on engine coolant temperature and A/C system high side pressure, both fans operate together at either low or high speeds. The radiator fan relays are controlled by the Powertrain Control Module (PCM). The PCM energizes the relays by switching their ground paths on and off.

With A/C off, the PCM energizes the low speed relay (turns fans on) when engine coolant temperature excedes 210° F (99° C). The PCM de-energizes the relay (turns fans off) when engine coolant temperature drops below 199° F (93° C).

With A/C off, the PCM energizes the high speed relay (turns fans on) when engine coolant temperature excedes 230° F (110° C). The PCM de-energizes the relay (turns fans off) when engine coolant temperature drops below 219° F (140° C).

With A/C on, the PCM energizes the low speed relay (turns fans on) when A/C system high side pressure excedes 210 PSI (1445 kPa). The PCM de-energizes the relay (turns fans off) when A/C system high side pressure drops below 125 PSI (861 kPa) if engine coolant is below 199° F (93° C).

With A/C on, the PCM energizes the high speed relay (turns fans on) when A/C system high side pressure excedes 250 PSI (1724 kPa). The PCM de-energizes the relay (turns fans off) when A/C system high side pressure drops below 230 PSI (1586 kPa)