2005 MITSUBISHI 380 Battery

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-83
NOTE: Also check intermediate connector A-13 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector A-13 is damaged, repair or
replace the connector as described in GROUP 00E, Harness
Connector Inspection P.00E-2.
Q: Is the wiring harness between A/C compressor clutch
relay connector B-18X (terminal 1) and the battery in
good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.
NO : Repair the wiring harness. Check that the air
conditioning works normally.
STEP 13. Check the wiring harness between A/C
compressor clutch relay connector B-18X (terminal 4) and
A/C compressor assembly connector B-28 (terminal 1).
Q: Is the wiring harness between A/C compressor clutch
relay connector B-18X (terminal 4) and A/C compressor
connector B-28 (terminal 1) in good condition?
YES : Go to Step 14.
NO : Repair the wiring harness. Check that the air
conditioning works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-85
STEP 16. Measure the voltage at A/C-ECU connector C-15.
(1) Disconnect A/C-ECU connector C-15 and measure the
voltage at the relay box side.
(2) Disconnect powertrain control module connector B-20 and
ground harness side terminal No.6.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between A/C-ECU connector C-15
terminal No.10 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Does the measured voltage correspond with this range?
YES : Go to Step 18.
NO : Go to Step 17.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-87
STEP 18. Check the air conditioning compressor clutch
operation.
Connect the compressor connector terminal to the battery posi-
tive (+) terminal and ground the battery’s negative (-) terminal
to the compressor unit. At that time, the air conditioning com-
pressor clutch should make a definite operating sound.
Q: Can the sound (click) of the air conditioning
compressor clutch operation be heard?
YES : Go to Step 19.
NO : Replace the compressor magnet clutch. Check that
the air conditioning works normally.
STEP 19. Check the air thermo sensor.
Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance val-
ues should generally match those in the graph.
NOTE: The temperature at the check should not exceed the
range in the graph.
Q: Is the air thermo sensor in good condition?
YES : Go to Step 20.
NO : Replace the air thermo sensor. Check that the air
conditioning works normally.
STEP 20. Check the ambient air temperature sensor.
Measure the resistance between the sensor terminals under at
least two temperatures. The resistance values should meet the
values shown.
NOTE: The temperature should be within the shown range.
Q: Is the ambient air temperature sensor in good
condition?
YES : Go to Step 22.
NO : Replace the ambient air temperature sensor. Check
that the air conditioning works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-91
STEP 2. Measure the voltage at blower motor connector
C-115.
(1) Disconnect blower motor connector C-115, and measure
the voltage at the wiring harness side.
(2) Disconnect A/C-ECU connector C-15 and ground harness
side terminal No.9.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between C-115 (terminal 1) and
ground.
The measured value should be approx. 12 volts (battery
positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 11.
NO : Go to Step 3.
STEP 3. Check blower relay connector C-202 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is blower relay connector C-202 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-92
STEP 4. Check the blower relay continuity.
Follow the table below to check the blower relay for continuity.
Q: Is the blower relay continuity in good condition?
YES : Go to Step 5.
NO : Replace the blower relay. The blower motor should
operate normally.
STEP 5. Measure the voltage at blower relay connector
C-202.
(1) Disconnect blower relay connector C-202, and measure the
voltage at the junction block side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 7.
NO : Go to Step 6. BATTERY
VOLTAGETESTER
CONNECTIONSPECIFIED
CONDITION
Not applied 4
5 Open circuit
Connect
terminal 1 to the
positive battery
terminal
Connect
terminal 3 to the
negative battery
terminal4
5 Less than 2 ohms

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-94
STEP 7. Measure the voltage at blower relay connector
C-202.
(1) Disconnect blower relay connector C-202, and measure the
voltage at the junction block side.
(2) Measure the voltage between terminal 5 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 9.
NO : Go to Step 8.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-97
NOTE: Also check junction block connector C-211 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-211 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between blower relay connector
C-202 (terminal 3) and A/C-ECU connector C-15
(terminal 9) in good condition?
YES : Go to Step 10.
NO : Repair the wiring harness. The blower motor should
operate normally.
STEP 10. Check the wiring harness between blower motor
connector C-115 (terminal 1) and blower relay connector
C-202 (terminal 4).
Q: Is the wiring harness between blower motor connector
C-115 (terminal 1) and blower relay connector C-202
(terminal 4) in good condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.
NO : Repair the wiring harness. The blower motor should
operate normally.
NOTE: Also check junction block connector C-215 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-215 is damaged,
repair or replace the connector as described in GROUP 00E,
Harness Connector Inspection P.00E-2.
STEP 11. Check the blower fan and motor operation.
When battery voltage is applied between the terminals, check
that the motor operates. Also, check that there is no abnormal
noise.
Q: Is there any abnormal noise?
YES : Go to Step 12.
NO : Replace the blower relay. The blower motor should
operate normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-111
STEP 2. Check defogger relay connector C-201 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is defogger relay connector C-201 in good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. The
defogger system should work normally.
STEP 3. Check the defogger relay continuity.
Follow the table below to check the defogger relay for continu-
ity.
Q: Is the defogger relay in good condition?
YES : Go to Step 4.
NO : Replace the defogger relay. The defogger system
should work normally.
BATTERY VOLTAGE CONNECT
TESTER
BETWEENSPECIFIED
CONDITION
Not applied 4
5 Open Circuit
Connect terminal 1
to the positive
battery terminal
Connect terminal 3
to the negative
battery terminal4
5 Less than 2 ohms