Komatsu PC200-8M0, Shop Manual

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100 Air conditioner
Information in troubleshooting table
80-100
42
PC200, 200LC, 220, 220LC-8M0
SEN06151-00
Information in troubleshooting table
Information in troubleshooting table
a
The following information is summarized in the troubleshooting table and the related electrical circuit dia-
gram. Before performing troubleshooting, understand that information fully.
a
If a wiring harness is burnt, replace it.
<Defective wiring harness>
q Open circuit
Connection of connector is defective or wiring harness is broken.
q Ground fault
A harness not to be connected to the ground (earth) circuit comes into contact with the ground (earth)
circuit or chassis accidentally.
q Hot short circuit
A harness not to be connected to the power (24 V) circuit comes into contact with the power (24 V) circuit
accidentally.
q Short circuit
An independent wire in the harness abnormally comes into contact with one of another wire. (Defective
insulation in connector or others)
Related circuit diagram
Failure Problem on machine
Related information Information related to detected failure or troubleshooting
Cause Procedure, measuring location, criteria and remarks
1
Probable causes of
failure
(Perform trouble-
shooting according
to these.)
<Information described>
q
Procedure
q
Measuring location
a
"Between A and B" means "Measure voltage or resistance and so on between A and B".
q
Standard value in normal condition to judge probable causes
q
Remarks required for judgement
<Notes on troubleshooting>
(1) Pin number description sequence and tester lead handling
For troubleshooting, connect the plus (+) and minus (–) tester leads as shown below unless
otherwise specified.
q
Connect the plus (+) lead to a pin or harness indicated in the front.
q
Connect the minus (–) lead to a pin or harness indicated in the rear.
(2) Example of troubleshooting by inspection of multiple items
a
Normal in 1 but abnormal in 2
At this time “- defective” shown at left is applied
2
3 - defective
This is the excerpted circuit diagram related to failure
q
Indicates connector No., and pin No.
q
See "Circuit diagram and arrangement of connector pins" and "Parts and connectors layout" for connector location
q The circuit diagram shows the size and colors of wires.
W: White, B: Black, R: Red, G: Green, Y: Yellow, L: Blue, V: Purple, P: Pink, O: Orange, Br: Brown, Gr: Gray, Sb:
Sky blue, Lg: Light green, Dg: Dark green, Ch: Dark brown
a
When there are two colors
Example: WY: Yellow line on white background
a
The number before the wire color indicates the wire size.
q N.C.: Normally closed (Normally ON)
q
[1], [2],··· are numbers of unlabeled connectors.
q Arrow (
↔
): Roughly indicates their mounting place on the machine.