RENR7299-11
February 2021
Harness And Wire Electrical Schematic Symbols
Symbols
T
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Circuit Breaker
Symbol
Flow
Symbol
Symbols and Definitions
Fuse: A component in an electrical circuit that will open the circuit if too much current flows
through it.
Switch (Normally Open): A switch that will close at a specified point (temp, press, etc.). The
circle indicates that the component has screw terminals and a wire can be disconnected from it.
Switch (Normally Closed): A switch that will open at a specified point (temp, press, etc.).
No circle indicates that the wire cannot be disconnected from the component.
Ground (Wired): This indicates that the component is connected to a grounded wire. The
grounded wire is fastened to the machine.
Ground (Case): This indicates that the component does not have a wire connected to ground.
It is grounded by being fastened to the machine.
Reed Switch: A switch whose contacts are controlled by a magnet. A magnet closes the
contacts of a normally open reed switch; it opens the contacts of a normally closed reed switch.
307D, 311D, 311F, 312D, 312D2, 313D,
313D2, 315D, 318D, 318D2, 319D,
320D, 320D2, 323D and 323D2
Excavators and M313D, M315D,
M316D, M318D and M322D Wheeled
Excavators
Air Conditioning Electrical System
Sender: A component that is used with a temperature or pressure gauge. The sender
measures the temperature or pressure. Its resistance changes to give an indication to
the gauge of the temperature or pressure.
T
Relay (Magnetic Switch): A relay is an electrical component that is activated by electricity.
It has a coil that makes an electromagnet when current flows through it. The
electromagnet can open or close the switch part of the relay.
Solenoid: A solenoid is an electrical component that is activated by electricity. It has a
coil that makes an electromagnet when current flows through it. The electromagnet
can open or close a valve or move a piece of metal that can do work.
Magnetic Latch Solenoid: A magnetic latch solenoid is an electrical component that is
activated by electricity and held latched by a permanent magnet. It has two coils (latch and unlatch)
that make electromagnet when current flows through them. It also has an internal switch that places
the latch coil circuit open at the time the coil latches.
Harness and Wire Symbols
Wire,
Cable,
or
Harness
Assembly Identification: Includes
Harness Identification Letters and
Harness Connector Serialization
Codes (see sample).
Harness Identification Letter(s):
(A, B, C, ..., AA, AB, AC, ...)
L-C12
3E-5179
AG-C4
111-7898
1
Part Number: for Connector Plug
L-C12
3E-5179
Part Number: for Connector Receptacle
2
Plug
PUBLICATIONS.CAT.COM
Harness Connector Serialization Code:
The "C" stands for "Connector" and the
number indicates which connector in the
harness (C1, C2, C3, ...).
5A
Receptacle
Pin or Socket Number
1
2
Deutsch connector: Typical representation
of a Deutsch connector. The plug contains all
sockets and the receptacle contains all pins.
1
2
Sure-Seal connector: Typical representation
of a Sure-Seal connector. The plug and receptacle
contain both pins and sockets.
Fuse (5 Amps)
Harness identification code:
This example indicates wire group 325,
wire 135 in harness "AG".
9X-1123
Component
Part Number
325-AG135 PK-14
Wire Gauge*
Wire Color
*Wire gauge is shown in AWG (American Wire Gauge)
but could also be shown in metric denoted with mm
© 2021 Caterpillar. All Rights Reserved. CAT, CATERPILLAR, LET’S DO THE WORK, their respective logos, “Caterpillar Corporate Yellow”, the
“Power Edge” and Cat “Modern Hex” trade dress as well as corporate and product identity used herein, are trademarks of Caterpillar and may not
be used without permission.
RENR7299-11
12 Page, (Dimensions: 25 inches x 24 inches)
1
1
BU/OR-20
PU/RD-20
BR/WH-20
BU/BK-20
BR/BK-20
PK-20
CONTROL PANEL
TYPE 2
PK/BK-20
CONN AA
S-BU-20
DETAIL OF CONN AA
Type 1
BK/YL-20
GY/BU-20
OR/BU-20
DETAIL OF CONN A
Type 1
DETAIL OF CONN AA
Type 2
BR/WH-20
BK-20
GY/YL-20
PK/GN-20
BK/YL-20
GY/BU-20
OR/BU-20
BU/OR-20
L-GN/YL-20
GY/YL-20
GY/YL-20
BK/YL-20
BK-20
BK/RD-20
DETAIL OF CONN G
DETAIL OF CONN H
DETAIL OF CONN J
DETAIL OF CONN A
Type 2
CONN C
CONN B
CONN CC
PK-18
S-BLU-20
PK/BK-20
CONN CC
CONN C
L-GN/RD-20
WH/RD-20
PU/GN-20
GY/YL-20
2
CONN HH
3
PU/YL-20
CONN GG
4
DETAIL OF CONN KK
DETAIL OF CONN K
1
2
CONN JJ
1
2
WH/YL-20
L-GN/YL-20
BU/OR-20
PU/RD-20
PK/BK-20
S-BU-20
PU/GN-20
WH/RD-20
L-GN/YL-20
WH/YL-20
PK/BK-20
BK/GN-20
PU/YL-20
L-GN/RD-20
BK/RD-20
PK-18
BR/BK-20
BU/BK-20
BR/WH-20
GY/YL-20
PK/GN-20
BK-20
BK/YL-20
GY/BU-20
OR/BU-20
WH/RD-20
PU/GN-20
WH/RD-20
PK/GN-20
1 2 3 4 5 6 7
CONN B
PU/RD-20
GY/BU-20
S-BU-20
BR/OR-20
PU/GN-20
BU/OR-20
PU/RD-20
PK/BK-20
S-BU-20
PU/GN-20
WH/RD-20
BR/OR-20
WH/YL-20
L-GN/YL-20
CONN BB
PK/BK-20
1
2
3
4
5
6
7
8
9
10
PU/RD-20
BK/GN-20
PU/YL-20
L-GN/RD-20
BK/RD-20
PK-20
BR/BK-20
BU/BK-20
BR/WH-20
GY/YL-20
PK/GN-20
BK-20
BK/YL-20
GY/BU-20
OR/BU-20
DETAIL OF CONN B
1
2
3
4
5
6
7
8
9
10
11
12
13
14
DETAIL OF CONN BB
BU/OR-20
PU/RD-20
PK/BK-20
S-BU-20
PU/GN-20
WH/RD-20
BR/OR-20
WH/YL-20
L-GN/YL-20
BU/BK-20
1
2
3
4
5
6
7
8
9
10
BR/WH-20
BR/ORN-20
L-GRN/YL-20
WH/YL-20
CONN BB
S-BU-20
DETAIL OF CONN GG
DETAIL OF CONN HH
DETAIL OF CONN JJ
BU/BK-20
BR/BK-20
L-GN/RD-20
BU/OR-20
BK/GRN-20
ORN/BLU-20
PK/GRN-20
GY/BLU-20
PU/YL-20
BK/YL-20
GY/YL-20
1 2
1 2
BR/BK-20
1
2
PK-20
BK/GN-20
PK-18
BK/RD-20
BK/GN-20
PU/YL-20
L-GN/RD-20
BK/RD-20
PK-18
BR/BK-20
BU/BK-20
BR/WH-20
GY/YL-20
PK/GN-20
BK-20
BK/YL-20
GY/BU-20
OR/BU-20
BK/RD-20
1 2
GY/YL-20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
PK/GN-20
BK-20
BR/WH-20
WH/YL-20
BK-20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
L-GN/RD-20
PU/YL-20
BK/GN-20
OR/BU-20
GY/YL-20
PU/YL-20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
CONN A
L-GRN/RD-20
BR/BK-20
BLU/BK-20
PU/GRN-20
WH/RD-20
PU/RD-20
BLU/ORN-20
GY/BU-20
BK/YL-20
BU/OR-20
PU/RD-20
PK/BK-20
S-BU-20
PU/GN-20
WH/RD-20
WH/YL-20
BR/OR-20
BK/GN-20
PU/YL-20
L-GN/RD-20
BK/RD-20
PK-20
BR/BK-20
BU/BK-20
BR/WH-20
BK-20
GY/YL-20
PK/GN-20
BK/YL-20
GY/BU-20
OR/BU-20
GY/YL-20
PK/GN-20
CONN AA
17
18
19
20
21
22
23
24
25
26
27
28
L-GN/YL-20
BK/RD-20
17 18 19 20 21 22
CONN A
PK/BK-20
S-BLU-20
PK-18
1 2 3 4 5 6 7 8
BR/OR-20
WH/YL-20
L-GN/YL-20
23 24 25 26 27 28
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
BK-20
9 10 11 12 13 14 15 16
BLU/ORN-20
PU/RD-20
WH/RD-20
PU/GRN-20
BLU/BK-20
BR/BK-20
CONTROL PANEL
TYPE 1
BK/GN-20
BK/GRN-20
ORN/BLU-20
PK/GRN-20
GY/BLU-20
PU/YL-20
BK/YL-20
GY/YL-20
BR/WH-20
BR/ORN-20
L-GRN/YL-20
WH/YL-20
WH/RD-20
L-GRN/RD-20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
PU/GN-20
BK/RD-20
L-GN/RD-20
PU/YL-20
DETAIL OF CONN C
DETAIL OF CONN CC
CONN J
OR/BU-20
GY/YL-20
BK-20
BK/RD-20
DETAIL OF CONN DD
GY/YL-20
PK/GN-20
GY/YL-20
BK/YL-20
OR/BU-20
CONN G
CONN H
GY/YL-20
GY/BU-20
BK/RD-20
BK-20
5
15
BR/WH-20
GY/YL-20
DETAIL OF CONN D
GY/YL-20
1
2
MOTOR
DETAIL OF CONN EE
5A
OR/BU-20
WH/RD-20
PU/GN-20
PU/YL-20
DETAIL OF CONN E
GY/YL-20
CONN E
CONN EE
2
1
CONN DD
OR/BU-20
GY/YL-20
OR/BU-20
GY/YL-20
DETAIL OF CONN F
BK/RD-20
BK-20
13
1
CONN D
L-GN/RD-20
OR/BK-20
14
BK/RD-20
BK-20
7
6
5
4
3
2
1
1 2 3 4 5 6 7
CONN KK
CONN K
S-BU-20
PK/BK-20
OR/BU-20
GY/YL-20
1
2
3
4
5
6
BK/RD-20
BK-20
BU/OR-20
L-GN/RD-20
1 2 3 4 5 6 7
BK/RD-20
BK-20
6
CONN F
RD-14
BK-14
OR/BK-18
12
RD/GN-16
PK-18
BK-14
OR/BK-20
RD-18
BK-18
CONN T
PK/BK-20
OR/BK-18
DETAIL OF CONN S
S-BU-20
1 2
BR/BK-20
BK/BU-14
4
2
BU/BK-20
DETAIL OF CONN N
DETAIL OF CONN NN
CONN LL
CONN L
7
1
2
3
4
5
6
7
8
9
10
11
12
15A
3
1
7
6
5
4
3
2
1
LIGHT
10A
DETAIL OF CONN MM
MOTOR
OR/BK-20
OR/BK-18
RD-14
RD/GN-16
PK-18
BK-14
Components List
Item
No. Description
Part#
(1)
1 Control Panel Assembly
2 Water Temperature Sensor
245-7831
3 Frost Sensor
245-7835
4 Recirculation Temperature Sensor 245-7815
5 Actuator
245-7817
6 Actuator
245-7813
7 Actuator
245-7817
8 Blower Control
245-7832
9 Blower Motor
245-7839
10 Blower Main Relay
196-1666
11 Clutch Solenoid Relay
196-1666
12 Refrigerant Compressor (1)
13 Pressure Switch
130-0270
14 Ambient Temperature Sensor
235-8874
(1)
15 Air Conditioner Group
MOTOR
PU/RD-20
BU/OR-20
BK/GN-20
L-GN/RD-20
CONN S
GY/YL-20
CONN M
7
6
5
4
3
2
1
CONN MM
CONN RR
CONN UU
10
11
BU/BK-20
BR/BK-20
BK-14
BK/BU-14
CONN P
CONN PP
MOTOR
9
CONN N
4
2
1
3
PK/BU-14
BK/BU-14
CONN R
4
1
3
2
4
1
3
2
CONN U
1
2
RD-14
OR/BK-20
WH/YL-20
PK/BU-14
NEG
OR/BK-20
0R/BK-20
L-GN/YL-20
RD/GN-16
POS
DETAIL OF CONN M
OR/BK-20
CONN FF
PU/RD-20
BK/GN-20
GY/YL-20
DETAIL OF CONN FF
RENR7299-11
DETAIL OF CONN LL
DETAIL OF CONN L
2
2
1
12 Page, (Dimensions: 25 inches x 24 inches)
OR/BK-20
CONN NN
8
(1) Refer to the parts manual for your machine for the current part numbers
OR/BK-20
RD/GN-16
OR/BK-20
3
1
RD-18
PK/BU-14
BK/BU-14
4
2
3
1
BK-18
DETAIL OF CONN T
L-GN/YL-20
OR/BK-20
WH/YL-20
DETAIL OF CONN UU
DETAIL OF CONN U
Callout Number
(52) VALVE GP - CONTROL
138-1234
Part Number
(Machine Location from
Component Locations Table)
SYMBOL
DESCRIPTION
CIRCUIT CONNECTED
CIRCUIT NOT CONNECTED
ELECTRICAL CONNECTION TO
MACHINE STRUCTURE
H#
RED
WH
WHITE
OR
ORANGE
YL
YELLOW
PK
PINK
CONNECTOR
BK
BLACK
CIRCUIT GROUPING DESIGNATION
SPLICE
BLADE, SPADE, RING OR SCREW
TERMINAL
1
DETAIL OF CONN RR
DETAIL OF CONN P
DETAIL OF CONN PP
Do not operate or work on this product unless you have
read and understood the instruction and warnings in the
relevant Operation and Maintenance Manuals and
relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or
death. Proper care is your responsibility.
COLOR
RD
INTERNAL ELECTRICAL CONNECTION
TO SURFACE OF COMPONENT
ATCH WIRE, CABLE, COMPONENT
/
ABBREV
Component
Name
2
PK/BU-14
RD-14
DETAIL OF CONN R
CALLOUT FORMAT IF APPLICABLE
4
2
GY
GRAY
PU
PURPLE
BR
BROWN
GN
GREEN
BU
BLUE
THIS SCHEMATIC IS FOR THE 307D, 311D, 311F, 312D, 312D2, 313D, 313D2, 315D, 318D,
318D2, 319D, 320D, 320D2, 323D AND 323D2 EXCAVATORS AND M313D, M315D, M316D,
M318D AND M322D WHEELED EXCAVATORS ELECTRICAL SYSTEM
MEDIA NUMBER: RENR7299-11
SCHEMATIC PART NUMBER: 235-8967, CHANGE: 02, VERSION: HE
SCHEMATIC PART NUMBER: 372-9415, CHANGE: 00, VERSION: HE
SCHEMATIC PART NUMBER: 420-7570, CHANGE: 00, VERSION: HE
Components are shown installed on a fully operable machine with the key and engine off, transmission shifter
in neutral and with parking brake set.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
Refer to the Parts Manual using a specific serial number prefix in SIS before ordering parts from this schematic.
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