
RENR9348-01 15
Troubleshooting Section
i02433503
Engine Wiring Information
SMCS Code: 1408
The wiring schematics are revised periodically.
Thewiringsche
matics will change as updates are
made to the engine’s harness. For the most current
information, always check the revision number of the
schematic. Us
e the schematic with the latest revision
number.
Harness Wire Identification
Caterpillar
identifies all wires with eleven solid colors.
The circuit number is stamped on the wire at a 25 mm
(1 inch) spacing. Table 6 lists the wire colors and the
color codes.
Table 6
Color Codes for the Harness Wire
Color Code Color Color Code Color
BK Black
GN Green
BR Brown BU Blue
RD Red PU Purple
OR Orange GY Gray
YL Yellow WH White
PK Pink
For example
, a wire identification of A701-GY on the
schematic would signify a gray wire with the circuit
number A701. A701-GY identifies the power circuit
for the No.
1 Injector solenoid.
Another wire identification on the schematic is the
size of the
wire. The size of the wire will follow the
wire color. Wire size or gauge is referred to as AWG
(American Wire Gauge). AWG is a description of the
diameter o
fthewire.
For example, a code of 150-OR-14 on the schematic
would indi
catethattheorangewireincircuit150isa
14 AWG wire.
If the gau
ge of the wire is not listed, the wire is 16
AWG.
Conversi
on of AWG Numbers to Metric
Measurements
Table7sh
ows the various AWG numbers that are
used for the wires. The metric equivalent for the
diameter of each AWG number are also shown.
Table 7
Metric Equivalents for AWG Numbers
AWG
Number
Diameter
(mm)
AWG
Number
Diameter
(mm)
20 0.8 14 1.6
18 1.0 12 2.0
16 1.3 4 3.2
Welding on Applications that are
Equipped with a n Electronic Control
Module (ECM)
Proper welding procedures are necessary in order
to avoid damage to the engine’s electronic control
module, sensors, and associated components.
Remove the component that requires welding. When
welding on an application that is equipped with an
ECM and removal of the component is not possible,
the following procedure must be followed. This
procedure provides the minimum amount of risk to
the electronic components.
NOTICE
Do not groun
d the welder to electrical components
such as the ECM or sensors. Improper grounding can
cause damage to the drive train bearings, hydraulic
component
s, electrical components, and other com-
ponents.
Clamp the g
round cable from the welder to the com-
ponent that will be welded. Place the clamp as close
as possible to the weld. This will help reduce the pos-
sibility
of damage.
1. Stop the engine. Remove the electrical power
from the E
CM.
2. Disconnect the negative battery cable from the
battery.
If a battery disconnect switch is installed,
open the switch.