Air Conditioner Does Not Operate Normally (Including Air Conditioner Abnormality Record) - Komatsu Galeo PC138US-8 Shop Manual

40 Troubleshooting
E-22 Air conditioner does not operate normally (including air
conditioner abnormality record)
Trouble (1) When air conditioner switch is operated, air conditioner control screen is not displayed.
Related • Condition of air conditioner switch signal can be checked with monitoring function.
information (Code: 04505 Monitor 3rd, 4th line switches, 04506 Monitor 5th line switch)
Possible causes
and standard
value in normal
1 Defective machine monitor
state
Trouble (2) When air conditioner switch is operated, air conditioner does not operate at all.
Related
information
1 Defective fuse No. 15
2 Defective fuse in unit
Disconnection in wiring har-
ness (Disconnection in wiring
3
or defective contact in con-
nector)
Possible causes
and standard
Ground fault in wiring har-
value in normal
4 ness (Short circuit with GND
state
circuit)
Defective air conditioner con-
5
troller
6 Defective machine monitor
PC138US, USLC-8
Cause Standard value in normal state/Remarks on troubleshooting
Machine monitor may be defective. (Since trouble is in system,
troubleshooting cannot be carried out.)
Cause Standard value in normal state/Remarks on troubleshooting
If fuse is broken, circuit probably has ground fault. (See cause 4.)
If fuse in unit is broken, circuit in unit probably has ground fault.
(See cause 4.)
a Prepare with starting switch OFF, then carry out troubleshoot-
Wiring harness between F01-15 – fuse in
unit – AC
Wiring harness between AC
(16) – chassis ground (T14)
a Prepare with starting switch OFF, then carry out troubleshoot-
Wiring harness between F01-15 – fuse in
unit – AC
end
a Prepare with starting switch OFF, then turn starting switch ON
If above voltage is normal, air conditioner controller may be defec-
tive.
If causes 1 – 5 are not detected, machine monitor may be defec-
tive. (Since trouble is in system, troubleshooting cannot be carried
out.)
ing without turning starting switch ON.
(wiring side) (6)
W
W
ing without turning starting switch ON.
(wiring side) (6), – circuit branch
W
and carry out troubleshooting.
AC (wiring side)
W
Between (6) – (16)
SEN02467-00
Resis-
tance
(wiring side) Resis-
tance
Resis-
tance
Voltage
20 – 30 V
1
Max. 1 z
Max. 1 z
Min. 1 Mz
39