1998 NISSAN PATROL Heather And Air Conditioner Workshop Manual

b. Con®rm that discharge air comes out according to the air dis-
tribution table at left.
Refer to ``Discharge Air Flow'' (HA-13).
NOTE:
Con®rm that the compressor clutch is engaged (visualinspec-
tion) and intake door position is at FRESH when the DEF
is selected.
Intake door position is checked in the next step.
4. Check recirculation
a. Press RECswitch.
Recirculation indicator should illuminate.
b. Listen for intake door position change (you should hear blower
sound change slightly).
5. Check temperature dial
a. Turn temperature dial counterclockwise until 18ÉC is displayed.
b. Check for cold air at discharge air outlets.
c. Turn temperature dial clockwise until 32ÉC is displayed.
d. Check for hot air at discharge air outlets.
RHA654FD
RHA521G
RHA522G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-71

6. Check AUTO mode
a. Press AUTO switch.
b. Display should indicate AUTO.
Con®rm that the compressor clutch engages (audio or visual
inspection).
(Discharge air and blower speed will depend on ambient,
in-vehicle, and set temperatures.)
7. Check FRESH switch
a. Press FRE switch.
FRESH indicator should illuminate.
b. Listen for intake door position change. (You should hear a slight
change in blower sound.)
8. Check A/C switch
a. Press A/C switch.
A/C indicator should illuminate.
b. Con®rm that the compressor clutch is engaged.
RHA523G
RHA524G
RHA525G
TROUBLE DIAGNOSESAUTO
Operational Check (Cont'd)
HA-72

A/C System
TROUBLE DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM:
+A/C system does not come on.
Inspection ¯ow
*1: HA-74 *2: HA-70
COMPONENT DESCRIPTION
Automatic ampli®er (Auto amp.)
The auto ampli®er has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motor, mode door motor, intake door
motor, blower motor and compressor are then controlled.
The auto ampli®er is unitized with control mechanisms. Signals
from various switches and Potentio Temperature Control (PTC) are
directly entered into auto ampli®er.
Self-diagnostic functions are also built into auto ampli®er to provide
quick check of malfunctions in the auto air conditioner system.
Potentio temperature control (PTC)
The PTC is built into the A/C auto amp. It can be set at an interval
of 1ÉC in the 18ÉC to 32ÉC temperature range by turning the tem-
perature dial. The set temperature is digitally displayed.
SHA019F
RHA629G
RHA746G
TROUBLE DIAGNOSESAUTO
HA-73

DIAGNOSTIC PROCEDURE
Auto amp. check
Check power supply circuit for auto amp. with ignition switch ON.
Measure voltage across terminal Nos.j
1,j2,j20and body ground.
Voltmeter terminal
Voltage
%@
j
1
Body ground Approx. 12V j2
j20
RHA632G
RHA633G
TROUBLE DIAGNOSESAUTO
A/C System (Cont'd)
HA-74

Mode Door Motor
TROUBLE DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR (LAN)
SYMPTOM:
+Air outlet does not change.
+Mode door motor does not operate normally.
Inspection ¯ow
*1: HA-13
*2: HA-70
*3: HA-64
*4: HA-65
*5: HA-66*6: HA-67
*7: HA-103
*8: HA-105
*9: HA-107
*10: HA-110*11: HA-79
*12: HA-65
*13: HA-77
*14: HA-70
*15: HA-69
SHA020F
TROUBLE DIAGNOSESAUTO
HA-75

SYSTEM DESCRIPTION
Component parts
Mode door control system components are:
1) Auto amp.
2) Mode door motor (LCU)
3) In-vehicle sensor
4) Ambient sensor
5) Sunload sensor
6) Intake sensor
System operation
The auto ampli®er receives data from each of the sensors. The ampli®er sends air mix door and mode door
opening angle data to the air mix door motor LCU and mode door motor LCU.
The air mix door motor and mode door motor read their respective signals according to the address signal.
Opening angle indication signals received from the auto ampli®er and each of the motor position sensors are
compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/
COLD or DEFROST/VENT operation is selected. The new selection data is returned to the auto ampli®er.
SHA006FA
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-76

Mode door control speci®cation
COMPONENT DESCRIPTION
The mode door motor is attached to the heater unit. It rotates so
that air is discharged from the outlet set by the auto ampli®er. Motor
rotation is conveyed to a link which activates the mode door.
CONTROL LINKAGE ADJUSTMENT
Mode door
1. Install mode door motor on heater unit and connect it to main
harness.
2. Set up code No.
in Self-diagnosis STEP 4. Refer to HA-67.
3. Move side link by hand and hold mode door in DEF mode.
4. Make sure mode door operates properly when changing from
code No.
toby pushing DEF switch.
VENT B/L B/L FOOT F/D DEF
RHA730G
RHA631G
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-77

DIAGNOSTIC PROCEDURE
SYMPTOM: Mode door motor and/or air mix door motor do not
operate normally.
CHECK POWER SUPPLY FOR AUTO
AMP. (LCU) SIDE.
Do approx. 12 volts exist between auto
amp. (LCU) terminalj
15and body ground?
Ye s
cNo
Replace auto amp. (LCU).
CHECK SIGNAL AUTO AMP. (LCU) SIDE.
Do approx. 5.5 volts exist between auto
amp. (LCU) terminalj
5and body ground?
Ye s
cNo
Replace auto amp. (LCU).
Note
CHECK POWER SUPPLY FOR MOTOR
SIDE.
Do approx. 12 volts exist between door
motor (LCU) harness terminalj
31and body
ground?
Ye s
Note
CHECK SIGNAL MOTOR SIDE.
Do approx. 5.5 volts exist between door
motor (LCU) terminalj
32and body ground?
Ye s
Note
CHECK MOTOR GROUND CIRCUIT.
Check harness continuity between door
motor (LCU) harness terminalj
3and body
ground.
OK
Disconnect the mode door motor and air
mix door motor connector.
CHECK THE MODE DOOR MOTOR
OPERATION.
Reconnect the mode door motor and con-
®rm the motor operation.
NGMode door motor operates nor-
mally.
cOK
Replace the air mix door
motor.
Disconnect the mode door motor.
CHECK THE AIR MIX DOOR MOTOR
OPERATION.
Reconnect the air mix door motor and con-
®rm the motor operation.
NGAir mix door motor operates nor-
mally.
cOK
Replace the mode door
motor.
Replace the auto amp. (LCU).
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
RHA636G
RHA635G
RHA638G
RHA637G
RHA639G
.
.
.
.
.
.
.
.
.
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-78