2005 MITSUBISHI 380 heater

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

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-112
STEP 4. Check choke coil connector D-11 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is choke coil connector D-11 in good condition?
YES : Go to Step 5.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. The
defogger system should work normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-113
STEP 5.Measure the voltage at choke coil connector D-11.
(1) Disconnect connector D-11, and measure the voltage at the
harness side.
(2) Disconnect A/C-ECU connector C-15 and ground harness
side terminal No.27.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between choke coil connector D-11
terminal No.1 and ground.
The measured value should be approximately 12 volts.
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 13.
NO : Go to Step 6.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-114
STEP 6. Measure the voltage at defogger relay connector
C-201.
(1) Disconnect defogger relay connector C-201, 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 8.
NO : Go to Step 7.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-115
STEP 7. Check the wiring harness between defogger relay
connector C-201 (terminal 5) and the fusible link (1).
NOTE: Also check intermediate connector C-31 and junction
block connector C-216 for loose, corroded, or damaged termi-
nals, or terminals pushed back in the connector. If intermediate
connector C-31 and junction block connector C-216 is dam-
aged, repair or replace the connector as described in GROUP
00E, Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between defogger relay connector
C-201(terminal 5) and the fusible link (1) 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 defogger
system works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-116
STEP 8. Measure the voltage at defogger relay connector
C-201.
(1) Disconnect defogger relay connector C-201, 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 10.
NO : Go to Step 9.
STEP 9. Check the wiring harness between defogger relay
connector C-201 (terminal 1) and ignition switch (IG2).

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-117
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.
Q: Is the wiring harness between defogger relay connector
C-201 (terminal 1) and ignition switch (IG2) 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 defogger
system works normally.
STEP 10. Check A/C-ECU connector C-15 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-15 in good condition?
YES : Go to Step 11.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the defogger system works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-118
STEP 11. Check the wiring harness between defogger relay
connector C-201 (terminal 3) and A/C-ECU connector C-15
(terminal 8).
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 defogger relay connector
C-201 (terminal 3) and A/C-ECU connector C-15
(terminal 8) in good condition?
YES : Go to Step 12.
NO : Repair or replace the wiring harness. Refer to
GROUP 00E, Harness Connector Inspection
P.00E-2. Check that the defogger system works
normally.