Toyota AT180 Series Repair Manual page 187

RADIATOR FAN AND AIR CONDITIONER (AUTOMATIC AIR CONDITIONER, FOR DIAL 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 CONDENSER FAN MOTOR
1 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 (DIAL TYPE BLOWER CONTROL SW (W/ 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 AUTO AMPLIFIER. AT THE SAME TIME, CURRENT ALSO FLOWS FROM GAUGE FUSE TO TERMINAL IG OF A/C AUTO AMPLIFIER,
TERMINAL B2 OF A/C CONTROL ASSEMBLY AND TERMINAL A1 OF A/C CONTROL ASSEMBLY.
* LOW SPEED OPERATION (OPERATION AT MANUAL)
CURRENT TO TERMINAL 3 OF HEATER RELAY FLOWING TO TERMINAL OF HEATER RELAY
ASSEMBLY TERMINAL B3
THIS CAUSES THE CURRENT TO TERMINAL 5 OF THE HEATER RELAY TO FLOW TO TERMINAL 4 OF HEATER RELAY
(5S–FE) OR TERMINAL 1 (4A–FE) OF BLOWER MOTOR
BLOWER RESISTOR TERMINAL 4
* HIGH SPEED OPERATION (OPERATION AT MANUAL)
CURRENT TO TERMINAL 3 OF HEATER RELAY FLOWS TO TERMINAL 1 OF HEATER RELAY
ASSEMBLY TERMINAL B3
AT THE SAME TIME, CURRENT FLOWING TO TERMINAL 5 OF THE HEATER RELAY FLOWS TO TERMINAL 4
OR TERMINAL 1 (4A–FE) OF BLOWER MOTOR
CONTROL ASSEMBLY TERMINAL B3
* MEDIUM SPEED OPERATION (OPERATION AT MANUAL M1, M2)
THE CURRENT TO TERMINAL 3 OF HEATER RELAY FLOWS TO TERMINAL 1 OF HEATER RELAY
ASSEMBLY TERMINAL B3
AS A RESULT, THE CURRENT TO TERMINAL 5 OF HEATER RELAY FLOWS TO TERMINAL 4
(4A–FE) OF BLOWER MOTOR
3 TERMINAL B4 OF A/C CONTROL ASSEMBLY
MEDIUM SPEED.
198
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 CONDENSER FAN MOTOR
TERMINAL 2 OF RADIATOR FAN MOTOR
TERMINAL 1
TERMINAL 3 GROUND, FLOWING TO EACH FAN MOTOR IN PARALLEL CAUSING THE COOLING FAN
GROUND AND TURNS THE HEATER RELAY ON.
GROUND, CAUSING THE BLOWER MOTOR TO ROTATE AT LOW SPEED.
GROUND, TURNING THE HEATER RELAY ON.
TERMINAL 1 (5S–FE) OR TERMINAL 2 (4S–FE)
GROUND, CAUSING THE BLOWER MOTOR TO ROTATE AT HIGH SPEED.
GROUND AND TURNS THE HEATER RELAY ON.
TERMINAL 1 (5S–FE) OR TERMINAL 2 (4A–FE)
TERMINAL B3
TERMINAL 2 TERMINAL 1 OF WATER TEMP. SW (FOR FANS CONTROL)
TERMINAL 3
TERMINAL 4 OF A/C FAN RELAY NO. 3
TERMINAL 1
TERMINAL 4 OF A/C FAN RELAY NO. 3
MOTOR TERMINAL 1 (5S–FE) OR TERMINAL 2 (4A–FE)
TERMINAL 1 OF BLOWER RESISTOR
GROUND AND CAUSES THE BLOWER MOTOR TO ROTATE AT
TERMINAL 4 TERMINAL 3 OF A/C PRESSURE
TERMINAL 2 (5S–FE) 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 B2 OF A/C CONTROL
TERMINAL B2 OF A/C CONTROL
TERMINAL 2 (5S–FE)
TERMINAL B5 OF A/C CONTROL
TERMINAL B2 OF A/C CONTROL
TERMINAL 2 (5S–FE) OR TERMINAL 1
TERMINAL 1
TERMINAL
TERMINAL
TERMINAL HR OF
TERMINAL 2
TERMINAL 1 OF
TERMINAL