(HIGH SPEED OPERATION)
WITH THE REAR A/C SW IS MOVED TO HIGH POSITION. CURRENT FLOWING THROUGH THE BLOWER MOTOR FLOWS. WITHOUT PASSING
THROUGH THE BLOWER RESISTOR. TO TERMINAL 2 OF THE REAR A/C SW ~ TERMINAL 3 ~ GROUND. SO THAT THE BLOWER MOTOR
TURNS AT THE HIGHEST SPEED.- AIR CONDITIONER OPERATION
WITH THE IGNITION SW ON. CURRENT FLOWING THROUGH THE A/C FUSE FLOWS THROUGH EACH COMPONENT TO TERMINAL 6 OF THE A/C
SW. AND TO TERMINAL 3. 4. 5 .6 AND 7 OF THE A/C ~PLIFIER.
(OPERATION OF FRONT A/C)
INPUT INTO THE A/C AMPLIFIER ARE ENGINE SPEED SIGNALS FROM THE IGNITER. THE EVAPORATOR TEMP. SIGNALS FROM THE A/C
THERMISTOR. WHEN THE ENGINE IS RUNNING. WITH THE A/C SW ON AND THE BLOWER SW AT THE DESIRED SPEED. A SIGNAL IS INPUT
TO TERMINAL II OF THE A/C AMPLIFIER. THIS CAUSES THE AMPLIFIER TO OPERATE AND THE MAGNETIC CLUTCH RELAY. MAGNETIC
VALVE (FRONT) AND A/C IDLE-UP VSV ALL TURN ON. AT THE SAME TIME. THE AlC CUT RELAY ALSO TURNS OFF AND THE CURRENT
FLOWING THROUGH THE A/C FUSE FLOWS TO TERMINAL 2 OF THE MAGNETIC CLUTCH RELAY ~ TERMINAL 4 ~ TERMINAL I OF
MAGNETIC CLUTCH ~ TERMINAL 2 ~ GROUND. CAUSING THE COMPRESSOR TO OPERATE.
IF THE ENGINE SPEED FALLS TO APPROX. 600 RPM OR BELOW. A SIGNAL IS INPUT THAT THE EVAPORATOR TEMP. IS LOW. OR A SIGNAL
IS INPUT THAT THE REFRIGERANT PRESSURE IS EITHER ABNORMALLY HIGH OR LOW. THE AMPLIFIER FUNCTIONS TO TURN A/C OPERATION
OFF.
(OPERATION OF REAR A/C )
INPUT INTO THE A/C AMPLIFIER ARE ENGINE SPEED SIGNALS AND EVAPORATOR TEMP. SIGNALS FROM THE A/C THERMISTOR. WHEN THE
ENGINE IS RUNNING. WITH A SIGNAL THAT REAR A/C SW IS ON INPUT TO TERMINAL 12. THE AMPLIFIER OPERATE AND THE MAGNETIC
CLUTCH RELAY. MAGNETIC VALVE (REAR) AND A/C IDLE-UP VSV TURN ON. AT THE SAME TIME. THE A/C CUT RELAY TURNS OFF AND THE
CURRENT FLOWING THROUGH THE A/C FUSE FLOWS THE SAME AS FOR THE FRONT A/C. CAUSING THE COMPRESSOR TO OPERATE.
(A/C CUT OPERATION DURING ENGINE START)
DURNING ENGINE CRANKING. CURRENT FLOWING THROUGH THE ST FUSE FLOWS TO TERMINAL 2 OF THE A/C CUT RELAY ~ TERMINAL
~ GROUND. TURNING THE RELAY ON. THIS CAUSES THE RELAY CONTACT TO OPEN. SO CURRENT FROM THE A/C FUSE DOES NOT FLOW
BEYOND TERMINAL 4. THE A/C DOES NOT OPERATE AND ENGINE LOAD IS REDUCED DURNING CRANKING.
SERVICE HINTS
FRONT HEATER RELAY
(I) 1-(I)2:CLOSED WITH HEATER BLOWER SW ON
A 4 AlC PRESSURE SW
1-2:0PEN ABOVE APPROX. 13.5KG/CM' (192PSI. 1323KPA)
CLOSED BELOW APPROX. 10KG/CM' (142PS I. 980KPA)
A 3 AIC MAGNET CLUTCH
1-2:APPROX. 3.7n
A 15 AIC AMPLI F I ER
4-GROPUND:APPROX. 12VOLTS WITH IGNITION SW AT ON POSITION
13-GROUND:ALWAYS CONTINUITY
AI6 AIC CUT RELAY
3-4:0PEN WITH IGNITION SW AT ST POSITION
AI9 AIC SW
5-6:CONTINUITY WITH A/C SW AT ON
A 19 HEATER BLOWER SW [AIC SWJ
5-6:CONTINUITY WITH HEATER BLOWER SW ON
1-5:CONTINUITY WITH HEATER BLOWER SW AT MI POSITION
2-5:CONTINUITY WITH HEATER BLOWER SW AT M2 POSITION
5-8:CONTINUITY WITH HEATER BLOWER SW AT HI POSITION
B 3 BLOWER RESISTOR
1-3:APPROX. 0.48n
3-2:APPROX. 0.94n
2-4:APPROX. 0.91n
R 5 REAR AIC RELAY
1-2:CLOSED WITH REAR A/C CONTROL SW ON
R 7 REFRIGERATOR AMPLIFIER
8-GROUND:APPROX. 12VOLTS WITH IGNITION SW ON
4-GROUND:ALWAYS CONTINUITY
RII REAR AlC CONTROL SW
1-4:CONTINUTY WITH REAR A/C CONTROL SW AT M POSITION
2-4:CONTINUTY WITH REAR A/C CONTROL SW AT HI POSITION
3-4:CONTINUTY WITH REAR A/C CONTROL SW AT M OR HI POSITION