Isuzu KB P190. Manual — part 37

1-114 HEATER AND AIR CONDITIONING

C24SE

RTW610XF000501

HEATER AND AIR CONDITIONING 1-115

MAGNETIC CLUTCH DOES NOT RUN (C24SE)

Replace

YES

• Are the A/C thermo (X-15), heater & A/C (X-11)
and A/C compressor (X-14) relay OK?

• Are the No. SBF 8 fuse (30A) and the No. EB-13
(10A) fuses OK?

YES

• Is the pressure switch (C-24) OK?

YES

• Are the A/C switch (B-57) and the fan switch (B-13)
OK?

NO

YES

• Is there continuity between the engine harness
connector terminal No.1 (E-2) and the engine room
harness connector terminal No.2 (X-14)?

• Disconnect the A/C compressor relay.

• Turn the ignition switch "ON" (Engine is running)

• A/C switch and fan control knob (fan switch "ON")

NO

Replace

NO

Defective switch or insufficient
refrigerant

NO

NO

Does the magnetic clutch
operate?

YES

Replace

• Disconnect the magnetic clutch connector.

• Is there battery voltage between the engine room
harness connector terminal No.1 (E-2) and ground?

Defective compressor

YES

NO

Defective magnetic clutch

• Is the electronic thermostat (C-55) OK?

Replace

NO

YES

1-116 HEATER AND AIR CONDITIONING

Open circuit between the No. EB-13
fuse and the engine room harness
connector terminal No.1 (X-14).

NO

YES

• Is there battery voltage between the engine room
harness connector terminal No.1 (X-14) and
ground?

YES

• Disconnect the A/C thermo relay.

YES

• Is there continuity between the ECM harness
connector terminal C24SE No. 14 (C-56) and the
engine room harness connector terminal No.4
(X-14)?

Open circuit between the No. EB-13
fuse and the engine room harness
connector terminal No. 3 (X-14).

NO

• Is there battery voltage the engine room harness
connector terminal No.3 (X-14) and ground?

YES

• Is there continuity between the ECM harness
connector terminal C24SE No. 26 (C-56) and the
engine room harness connector terminal No. 1
(X-15)?

Open circuit between the ECM
harness connector terminal C24SE
No.14 (C-56) and the engine room
harness connector terminal No. 4 (X-
14).

NO

YES

• Is there battery voltage between the engine room
harness connector terminal No. 2 (X-15) and
ground?

Open circuit between the ECM
harness connector terminal C24SE
No. 26 (C-56) and the engine room
harness connector terminal No. 1 (X-
15).

NO

YES

• Is there continuity between the engine room
harness connector terminal No. 3 (X-15) and the
engine room harness connector terminal No. 1 (C-
24).

Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 2 (X-15).

NO

• Disconnect the ECM harness connector.

• Disconnect the pressure switch?

Open circuit between the engine harness
connector terminal No.1 (E-2) and the
engine room harness connector terminal
No.2 (X-14).

NO

HEATER AND AIR CONDITIONING 1-117

YES

• Disconnect the condenser fan relay connector condenser
fan.

YES

• Is there battery voltage between the engine room
harness connector terminal NO. 3 (C-24) and ground?

Open circuit between the condenser fan
relay No.3 (X-10) and engine room harness
connector terminal No. 4 (C-24).

NO

• Is there continuity between the relay terminal No. 3 (X-
10) and engine room harness connector terminal No.4
(C-24)?

YES

Open circuit between the No. EB-13 fuse
and engine room harness connector
terminal No. 3 (C-24).

NO

YES

• Is there continuity between the engine room harness
connector terminal No. 2 (C-55) and the engine room
harness connector terminal No. 2 (C-24)?

Open circuit between the engine room
harness connector terminal No. 4 (X-15)
and the engine room harness connector
terminal No. 1 (C-24).

NO

• Disconnect the pressure switch.

• Is there continuity between the engine room harness
connector terminal No. 4 (X-15) and the engine room
harness connector terminal No. 1 (C-24).

Open circuit between the No. EB-13 fuse
and the engine room harness connector
terminal No. 2 (X-15).

NO

• Connect the A/C thermo relay connector.

• Disconnect the electronic thermostat.

Open circuit between the engine room
harness connector terminal No.3 (X-15)
and the engine room harness connector
terminal No. 1 (C-24).

NO