Radiator Cooling Fan: Description and Operation

Cooling Fan Operation

When the ignition sw is turned on:
- the current from ign fuse flows to terminal 3 of Cooling Fan Relay No.3
--> terminal 1
--> terminal 1 of Water Temp. Switch (for cooling fan)
--> terminal 2
--> ground, from terminal 1 of Cooling Fan Relay No.2
--> terminal 2
--> terminal 1 of Water Temp. Switch (for Cooling Fan)
--> terminal 2
--> ground, and also from terminal 1 of Cooling Fan Relay No.1
--> terminal 2
--> terminal 2 of A/C Pressure Switch (high pressure)
--> terminal 3
--> ground. causing Cooling Fan Relays No.1. 2 and 3 to turn on.
At that time, the current from FL RDI fan flows to termimal 3 of Cooling Fan Relay No.2 and terminal 1 of Cooling Fan Motor No.1
--> terminal 2
--> termimal 4 of Cooling Fan Relay No.3
--> terminal 5
--> terminal 3 of Cooling Fan Relay No.1

Operation At Low Speed
During a/c operation, when the pressure of a/c compressor becomes higher (more than 13.5 kg/square cm, 1323 KPa, 192 Psi) than normal pressure,
the A/C High Pressure Switch turns off.
- As a result, Cooling Fan Relay No.1 turns off and the current flows from FL RDI fan:
--> terminal 1 of Cooling Fan Motor No.1
--> terminal 2
--> terminal 4 of Cooling Fan Relay No.3
--> terminal 5
--> terminal 3 of Cooling Fan Relay No.1
--> terminal 4
--> terminal 1 of Cooling Fan Motor No.2
--> terminal 2
--> ground, flowing to the fan motor in series, causing the cooling fan to rotate at low speed.

Operation At High Speed
When the engine coolant temperature becomes more than about 90° C (194° F) the water temp. switch turns off.
- As a result, Cooling Fan Relays No.2 and No.3 turn off, and current flows from FL RDI fan to terminal 1 of Cooling Fan Motor No.1
--> termimal 2
--> terminal 4 of Cooling Fan Relay No.3
--> terminal 2
--> ground. At the same time, current flows from FL RDI fan to termimal 3 of Cooling Fan Relay No.2
--> terminal 4
--> terminal 1 of Cooling Fan Motor No.2
--> terminal 2
--> ground, the current flowing to the fan motor in parallel causing the cooling fan to rotate at high speed.