Toyota ST185 Series Repair Manual page 163

RADIATOR FAN AND AIR CONDITIONER (MANUAL AIR CONDITIONER, FOR PUSH TYPE OF BLOWER CONTROL SW)
SYSTEM OUTLINE
1. COOLING FAN OPERATION
WHEN THE IGNITION SW IS TURNED ON, THE CURRENT FROM IGN FUSE FLOWS TO TERMINAL 3 OF RADIATOR FAN RELAY NO. 1
TERMINAL 4 TERMINAL 3 OF THE A/C PRESSURE SW
TERMINAL 2 (5S–FE)
SW TERMINAL 2 TERMINAL 1 OF WATER TEMP. SW (FOR FANS CONTROL)
RELAY NO. 1 AND RELAY NO. 2 OF EACH FAN TO TURN ON.
* OPERATION AT LOW SPEED
WHEN THE A/C SW (A/C CONTROL ASSEMBLY) IS TURNED ON AND THE AIR CONDITIONER OPERATES, THE CURRENT FLOWS
FROM GAUGE FUSE FLOWS TO TERMINAL 2 OF A/C MAGNET CLUTCH RELAY
CAUSING A/C MAGNET CLUTCH RELAY TO TURN ON.
AT THAT TIME, THE CURRENT FROM GAUGE FUSE FLOWS TO TERMINAL 4 OF A/C MAGNET CLUTCH RELAY
TERMINAL 4 OF A/C MAGNET CLUTCH
FAN RELAY NO. 3 TERMINAL 3
AS A RESULT, A/C MAGNET CLUTCH AND A/C FAN RELAY NO. 3 TURNS ON AND THE CURRENT FLOWS FROM FL CDS FAN
TERMINAL 2 OF A/C CONDENSER FAN MOTOR
1 OF A/C FAN RELAY NO. 2
TO EACH FAN MOTOR IN SERIES, CAUSING THE COOLING FAN TO ROTATE AT LOW SPEED.
* OPERATION AT HIGH SPEED
DURING A/C OPERATION, WHEN THE PRESSURE OF A/C COMPRESSOR BECOMES HIGHER THAN NORMAL PRESSURE (MORE
2
THAN 14.3 KG/CM 1401 KPA, 203 PSI), THE A/C PRESSURE SW TURNS OFF.
AS A RESULT, FAN RELAY NO. 1 AND NO. 2 TURNS OFF AND THE CURRENT FLOWS FROM FL RDI FAN
FAN RELAY NO. 1 TERMINAL 2
TERMINAL 2 OF A/C CONDENSOR FAN MOTOR
OF A/C FAN RELAY NO. 2
TO ROTATE AT HIGH SPEED. WHEN THE ENGINE COOLANT TEMPERATURE BECOMES MORE THAN ABOUT 90°C (194°F), THE
WATER TEMP. SW TURNS OFF AND THE SAME OPERATION AS ABOVE IS PERFORMED.
2. HEATER BLOWER MOTOR OPERATION PUSH TYPE BLOWER CONTROL SW (W/O AUTO A/C)
CURRENT IS APPLIED AT ALL TIMES THROUGH THE HEATER FUSE TO TERMINAL 5 OF HEATER RELAY. WHEN THE IGNITION SW IS
TURNED ON, CURRENT FLOWS THROUGH GAUGE FUSE TO TERMINAL 3 OF HEATER RELAY
A/C CONTROL ASSEMBLY.
AT THE SAME TIME, CURRENT ALSO FLOWS FROM GAUGE FUSE TO TERMINAL 5 OF A/C BLOWER CONTROL RELAY
TERMINAL C1 OF A/C CONTROL ASSEMBLY, FROM TERMINAL 5 OF BLOWER CONTROL RELAY
OF A/C CONTROL ASSEMBLY, AND ALSO FROM TERMINAL 5 OF BLOWER CONTROL ASSEMBLY.
* LOW SPEED OPERATION (OPERATION AT MANUAL)
WHEN THE BLOWER SW (A/C CONTROL ASSEMBLY) IS MOVED TO LOW POSITION, THE CURRENT FLOWING TO TERMINAL C3 OF
A/C CONTROL ASSEMBLY FLOWS TO TERMINAL C10 OF A/C CONTROL ASSEMBLY
ON.
THIS CAUSES THE CURRENT FLOWING FROM THE HEATER FUSE TO TERMINAL 5 OF THE HEATER RELAY TO FLOW TO TERMINAL
4 OF HEATER RELAY TERMINAL 4
* HIGH SPEED OPERATION (OPERATION AT MANUAL)
WHEN THE BLOWER SW (A/C CONTROL ASSEMBLY) IS MOVED TO HI POSITION, CURRENT FLOWS FROM TERMINAL C3 OF A/C
CONTROL ASSEMBLY TERMINAL C10 OF A/C CONTROL ASSEMBLY
AS A RESULT, THE CURRENT FLOWING TO TERMINAL C1 OF THE A/C CONTROL ASSEMBLY FLOWS TO TERMINAL C10 OF A/C
CONTROL ASSEMBLY GROUND, TURNING THE A/C BLOWER CONTROL RELAY ON.
THIS CASE IS THE CURRENT FLOWING FROM THE HEATER FUSE TO TERMINAL 5 OF THE HEATER RELAY TO FLOW TO TERMINAL 4
OF RELAY TERMINAL 2 OF BLOWER MOTOR
GROUND, CAUSING THE BLOWER MOTOR TO ROTATE AT HIGH SPEED.
166
GROUND, FROM TERMINAL 2 OF A/C FAN RELAY NO. 2
GROUND, AND FROM TERMINAL 1 OF A/C MAGNET CLUTCH RELAY
GROUND.
TERMINAL 1
TERMINAL 5 TERMINAL 2 OF A/C CONDENSOR FAN MOTOR
TERMINAL 2 OF RADIATOR FAN MOTOR
TERMINAL 1
TERMINAL 3 GROUND, FLOWING TO EACH FAN MOTOR IN PARALLEL CAUSING THE
GROUND, CAUSING THE BLOWER MOTOR TO ROTATE AT LOW SPEED.
TERMINAL 1
TERMINAL 2 TERMINAL 1 OF WATER TEMP. SW (FOR FANS CONTROL)
TERMINAL 4
TERMINAL 2 (5S–FE)
TERMINAL 3
TERMINAL 4 OF A/C FAN RELAY NO. 3
TERMINAL 1
TERMINAL 4 OF A/C FAN RELAY NO. 3
GROUND AND TURNS THE HEATER RELAY ON.
TERMINAL 4 OF BLOWER CONTROL RELAY
TERMINAL 3 OF A/C PRESSURE
GROUND, CAUSING
TERMINAL 8 OF A/C AMPLIFIER
TERMINAL 2 OF A/C
TERMINAL 1
TERMINAL 1 GROUND, FLOWING
TERMINAL 1 OF RADIATOR
GROUND, AND FROM FL CDS FAN
TERMINAL 1 TERMINAL 1
TERMINAL 1 TERMINAL C3 OF
TERMINAL 8
GROUND AND TURNS THE HEATER RELAY
TERMINAL 1
TERMINAL
COOLING FAN
TERMINAL 7
TERMINAL C8
TERMINAL 3