Condenser Fan: Description and Operation

System Outline

With the ignition SW turned on, the current through the ECU-IG fuse flows to the FAN NO.1 relay (Coil side), FAN NO.2 relay (Coil side) and FAN NO.3 relay (Coil side).

1. LOW SPEED OPERATION
Only when the A/C system is activated, the A/C condenser fan motor and the radiator fan motor rotates at low speed. When the A/C system is activated, the current from ECU-IG fuse flows to the FAN NO.3 relay (Coil side) to TERMINAL 2 of the diode (A/C) to TERMINAL 3 to TERMINAL (A) 16 of the engine control module, causing the FAN NO.3 relay to turn on. As a result, the current through the CDS FAN fuse flows to FAN NO.3 relay (Point side) to TERMINAL 2 of the A/C condenser fan motor to TERMINAL 1 to TERMINAL 3 of the FAN NO.2 relay to TERMINAL 4 to TERMINAL 2 of the radiator fan motor to TERMINAL 1 to GROUND. As this flowing in series for the motors, the motors rotate at low speed.

2. HIGH SPEED OPERATION
With the A/C single pressure SW is turned on and/or the water temp. SW is turned on, the A/C condenser fan motor and the radiator fan motor rotate at high speed.

When the A/C single pressure SW is turned on, the current through the ECU-IG fuse flows to the FAN NO.1 and NO.2 relay (Coil side) to TERMINAL 3 of the A/C single pressure SW to TERMINAL 2 to GROUND, and the current through the ECU-IG fuse flows to the FAN NO.3 relay (Coil side) to TERMINAL 2 of the diode (A/C) to TERMINAL 1 to TERMINAL 3 of the A/C single pressure SW to TERMINAL 2 to GROUND. As a result, FAN NO.1, NO.2. and NO.3 relay is turned on. At the same time, the current from the RDI FAN fuse flows to FAN NO.1 relay (Point side) to TERMINAL 2 of the radiator fan motor to TERMINAL 1 to GROUND, and the current from the CDS FAN fuse flows to FAN NO.3 relay (Point side) to TERMINAL 2 of the A/C condenser fan motor to TERMINAL 1 to TERMINAL 3 of the FAN NO.2 relay to TERMINAL 5 to GROUND.

As the current flowing in parallel for motors as above, the motors rotate at high speed.
When the water temp. SW is turned on, the current through the ECU-IG fuse flows to the FAN NO.1 and NO.2 relay (Coil side) to TERMINAL 2 of the water temp. SW to TERMINAL 1 to GROUND, and the current through the ECU-IG fuse flows to the FAN NO.3 relay (Coil side) to TERMINAL 2 of the diode (A/C) to TERMINAL 1 to TERMINAL 2 of the water temp. SW to TERMINAL 1 to GROUND. As a result, FAN NO.1, NO.2 and NO.3 relay is turned on. At the same time, the current from the RDI FAN fuse flows to FAN NO.1 relay (Point side) to TERMINAL 2 of the radiator fan motor to TERMINAL 1 to GROUND, and the current from the CDS FAN fuse flows to FAN NO.3 relay (Point side) to TERMINAL 2 of the A/C condenser fan motor to TERMINAL 1 to TERMINAL 3 of the FAN NO.2 relay to TERMINAL 5 to GROUND.
As the current flowing in parallel for motors as above, the motors rotate at high speed.