Component Location - Volume 1 Component
Schematic Location
Machine Location
Alarm - Travel / HCR
I-14
1
Sensor - Brake System Pressure
I-3
84
Alternator
C-16
2
Sensor - Fan Speed
H-14
85
Antenna - Product Link
H-16
3 (V2)
Sensor - Hydraulic Oil Temperature
G-14
86
Batteries
C-15
4
Sensor - Left ATCH Pedal Position
I-3
87
Camera - Rear View
D-16
5
Sensor - Transmission Output Speed
A-14
88
Coil - Exciter (MSS)
E-1
6
Sensor - Transmission Pressure
F-12
89 90
Control - Engine
D-15
7
Sensor - Travel Pedal Position
I-3
Control - Generator 15 KW
J-16
8 (V2)
Socket - 12V / 5A
C-3
91
Control - Implement
J-8
9
Solenoid - A/C Clutch
D-16
92
Control - Machine
J-10
10
Solenoid - Aux Port A Flow / Hammer
B-12
93
Control - MSS Keyreader
D-1
11
Solenoid - Aux Port A Line Release Pres
B-12
94
Control - Product Link
G-16
12 (V2)
Solenoid - Aux Port B Flow
B-12
95
Control Box - Generator 12.5KW
F-16
13
Solenoid - Aux Valve Directional
B-12
96
Converter - 24V to 12V
D-7
14
Solenoid - Aux Valve Load Sense
B-12
97
Diode - Wiper Cut Off
C-9
15
Solenoid - Boom Float
E-12
98
Fuse - Alternator
D-15
16
Solenoid - Boom Float Down
E-12
99
Fuse - Engine Control
C-15
17
Solenoid - Dozer Blade Lockout (Rear)
A-16
100
Fuse - Glow Plug
D-15
18
Solenoid - Generator 12.5 KW
H-16
101 (V2)
Fuse - Main Power
D-15
19
Solenoid - Generator 15 KW
H-16
102 (V2)
Fuse - Reserve
C-15
20
Solenoid - HCR Lower
D-12
104
Fuse - Starter Relay
D-15
21
Solenoid - HCR Raise
D-12
105
Fuse Panel - Battery (+24V)
B-9
22
Solenoid - Heavy Lift
G-12
106
Fuse Panel - Key Switch On (+24V)
B-11
23
Solenoid - Hyd Fan (RVS)
G-14
107 (V2)
Generator - 12.5 kw
H-16
24 (V2)
Solenoid - Hydraulic Fan
G-14
108
Generator - 15 kw
J-13
25 (V2)
Solenoid - Hydraulic Modulation
E-13
109
Glow Plugs
D-14
26
Solenoid - Implement Lockout
G-12
110
A-5
27
Solenoid - Joystick Steering Left
C-12
111
Ground - Cab Basic RH Rear Ground - Chassis 1 LH Front
I-3
28
Solenoid - Joystick Steering Protection
B-12
112
Ground - Chassis 2 LH Center
H-5
29
Solenoid - Joystick Steering Right
C-12
113
Ground - Chassis 3 RH Front
C-1
30
Solenoid - Main Pump Power Shift Pressure
F-12
114
Ground - Chassis 4 RH Center
C-16
31
Solenoid - Medium Pressure Port A
D-12
115
Ground - Engine 1
C-16
32
Solenoid - Medium Pressure Port B
D-12
116
Ground - Engine 2
C-16
33
Solenoid - MH Dozer Front Lock
A-13
117
Ground - Fuse / Relay Base
D-10
34
Solenoid - Oscillating Axle
G-12
118
Ground - Operator Platform
I-2
35
Solenoid - Quick Coupler
D-2
119
Ground - Undercarriage
A-13
36
Solenoid - Reverse Fan
G-14
120 (V2)
Joystick - L.H.
H-16
37
Solenoid - Stabilizer Lockout (Left Front)
A-13
121
Joystick - R.H.
F-1
38
Solenoid - Stabilizer Lockout (Left Rear)
A-16
122
LED - 12.5 KW Genset Magnet Control
E-2
39 (V2)
Solenoid - Stabilizer Lockout (Right Front)
A-13
123
LED - 15 KW Magnet GND Fault (-)
E-2
40 (V2)
Solenoid - Stabilizer Lockout (Right Rear)
A-16
124
LED - 15 KW Magnet GND Fault (+)
E-2
41
Solenoid - Swing Brake
G-12
125
Module - Switch Panel
C-4
42
Solenoid - Swing Pump Power Shift Pressure
F-12
126
Monitor - Operator
B-3
43
Solenoid - Transmission Gear Shift 1
G-12
127
G-12
128
I-3
129
Motor - Auto Lube Pump
H-14
44 (V2)
Solenoid - Transmission Gear Shift 2
Motor - Refueling Pump
H-14
45 (V2)
Solenoid - Travel Lock Magnet
Motor - Starter
C-16
46
Solenoid - Travel Motor Swash Plate Angle L
F-12
130
Motor - Washer
H-14
47
Solenoid - Travel Pilot Pressure
F-12
131
Motor - Wiper
J-1
48
Suppressor - A/C
D-16
132
Potentiometer - Magnet Drop Time
B-3
49 (V2)
Switch - Air Filter Clog Pressure
C-2
133
Relay - Auto Lube
A-10
50
Switch - Armrest position
H-16
134
Relay - Beacon
A-10
51
Switch - Boom Down Pilot Pressure
D-12
135
Relay - Boom Lamp
C-10
52
Switch - Brake Oil Accumulation Pressure
I-3
136
Relay - Brake Light
B-10
53
Switch - Disconnect
C-15
137
Relay - Flasher
F-11
54
Switch - Dozer Blade Lockout (Rear)
G-1
138
Relay - Front Cab Flood Lamp
C-10
55
Switch - Flood Lights
A-4
139
Relay - Hi Beam LH
D-11
56
Switch - Generator Enable
A-4
140 (V2)
Relay - Hi Beam RH
D-11
57
Switch - Ground Level Shut Down
I-14
141
Relay - Horn
C-10
58
Switch - Hazard
A-3
142
Relay - Hydraulic Fan Reverse
F-11
59 (V2)
Switch - HCR Door
I-14
143 144
Relay - Implement Lockout
B-10
60
Switch - HCR Enable
G-2
Relay - Interval Wiper
E-11
61
Switch - HCR Position
F-6
145
Relay - Lowbeam LH
D-11
62
Switch - Head Lamp
A-4
146
Relay - Lowbeam RH
D-11
63
Switch - Hydraulic Oil Clog Pressure
G-14
147 148
Relay - Main Power
E-10
64
Switch - Joystick Steering Enable
G-1
Relay - MH Dozer Front 1
B-16
65
Switch - Key
E-1
149
Relay - MH Dozer Front 2
B-16
66
Switch - Lever
J-1
150
Relay - MH Dozer Front 3
A-16
67
Switch - Main Pump Pressure
G-12
151
Relay - Position Light LH
E-11
68
Switch - Medium Pressure/2nd High
A-5
152
Relay - Position Light RH
E-11
69
Switch - Mirror Heater
F-1
153
Relay - Refueling Pump
F-10
70
Switch - Radio On/Off
F-2
154
Relay - Start Aid Control
C-13
71
Switch - Refueling Pump
F-10
155 (V2)
Relay - Starter
C-13
72
Switch - Seat / Heat Control
F-1
156
Relay - Travel Alarm / HCR
B-10
73
Switch - Seat Control
F-1
157
Relay - Wiper Cut Off
B-10
74
Switch - Stabilizer Lockout (Left Front)
G-2
158
Resistor - Alternator
C-3
75
Switch - Stabilizer Lockout (Left Rear)
G-1
159
Resistor - CAN BUS A #1
D-13
76
Switch - Stabilizer Lockout (Right Front)
G-1
160
Resistor - CAN BUS A #2
B-3
77
Switch - Stabilizer Lockout (Right Rear)
G-1
161
Resistor - CAN BUS B #1
J-12
78
Switch - Swing Pilot Pressure
G-12
162
Resistor - CAN BUS B #2
B-3
79
Switch - Window Lower Limit
C-3
163
Resistor - Fan Speed
H-14
80 (V2)
Switch - Window Upper Limit
E-5
164
Swivel - Electric
B-14
165
Sender - Fuel Level
I-14
81
Sensor - Boom Cylinder Head End Pressure
D-2
82
Sensor - Boom Cylinder Rod End Pressure
C-12
83
UENR1270-01 June 2012
116
159
105
134 138
111
15
115
70
CONN: 44
158
161
160 148 144
37
CONN: 45
64 54 61 69
104
164
52 113
63
59 55
MEDIUM PRESSURE CONTROL
60 125
106 110 127 128
57
53
68 34
73 151
58
CAB ROOF LINER
56
50
M318D MH and M322D MH Material Handler Electrical System
43
62
74
14
CONN: 61
M318D MH: D9X1-UP
150
118 162
23
89
51
22
163
CONN: 33 CONN: 49
CONN: 18
79
CONN: 29
CONN: 31 CONN: 28
77
CONN: 25
130 126 114 131
156 154 157 RELAY AND FUSE PANEL
78
9
149
38 Volume 1 of 2: Cab and Chassis
PILOT CONTROL MANIFOLD
47
M322D MH: D3X1-UP
153 © 2012 Caterpillar, All Rights Reserved
OPERATOR COMPARTMENT
90
Printed in U.S.A.
48 CONN: 60
10 6
Harness And Wire Electrical Schematic Symbols
CAB LH FRONT VIEW
Symbols Connector Location - Volume 1 Connector Number
Schematic Location
CONN 1A
27
11
91
152 139 146 142
42
T
Pressure Symbol
B-16 , B-14
CONN 1B
B-14
CONN 2
H-16
CONN 3 (On Volume 2)
J-16
CONN 4 (On Volume 2)
J-16
CONN 5 (On Volume 2)
I-15
CONN 6 (On Volume 2)
J-15
CONN 7
B-14
CONN 8
F-14
CONN 9
F-14
CONN 10 (On Volume 2)
G-14
CONN 11
B-13
CONN 12
B-13
CONN 13
D-13
CONN 14 (On Volume 2)
F-12
CONN 15
F-12
CONN 16 (On Volume 2)
F-12
CONN 17 (On Volume 2)
E-12
CONN 18 (On Volume 2)
E-10
CONN 19
E-9
CONN 20
E-9 D-9
CONN 22
D-9
CONN 23
D-9
CONN 24
G-9
CONN 25
F-9
CONN 26
G-9
CONN 27
G-8
CONN 28
F-8
CONN 29
F-8
CONN 30
G-8
CONN 31
F-8
CONN 32 (On Volume 2)
F-7
CONN 33 (On Volume 2)
F-7
CONN 34
G-7
CONN 35 (On Volume 2)
G-6
CONN 36
F-6
CONN 37
G-6
CONN 38
G-6
CONN 39
F-6
CONN 40 (On Volume 2)
G-6
CONN 41
G-5
CONN 42
F-5
CONN 43 (On Volume 2)
F-5
CONN 44
E-5
CONN 45
E-5
CONN 46
F-5
CONN 47
I-4
CONN 48
F-4
CONN 49
F-4
CONN 50
E-4
CONN 51 (On Volume 2)
F-4
CONN 52 (On Volume 2)
F-4
CONN 53
D-3
CONN 54
D-3
CONN 55
D-3
CONN 56
D-3
CONN 57 SERVICE CONNECTOR
C-3
CONN 58
C-2
CONN 59
D-2
CONN 60
I-2
CONN 61
H-2
CONN: 55
CONN: 50
29
141 143
REAR OF CAB
129
CONN: 39
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.
87
MACHINE SECURITY SYSTEM
Ground (Case): This indicates that the component does not have a wire connected to ground. It is grounded by being fastened to the machine.
CONN: 19 136
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.
84
35 28
CONN: 42 85
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.
CONN: 20
CONN: 30
1
CONN: 61
108
195-7747
Solenoid:
CONN: 55
Part Number: for Connector Receptacle
Plug
82
CONN: 53
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.
5A 9X-1123
Fuse (5 Amps)
132 92
33
Harness identification code: This example indicates wire group 325, wire 135 in harness "AG".
BOOM MOUNT VIEW
CONN: 8
CONN: 58
2
CONN: 9
195-9089
Solenoid:
279-6832
Solenoid:
291-5803
Solenoid:
322-5722
Solenoid:
Generator 12.5 KW
2.4 at 12 VDC 400 at 24 VDC
322-6342
Solenoid:
Aux Port A , B Flow Hammer Genrator 15 KW
2.4 at 12 VDC 120 at 24 VDC
342-4355
Resistor:
Fan Speed
34.9
Hydraulic Fan (RVS) Aux Port A Line Relief Pressure Aux Valve Load Sense Pressure
147
98
20.9 ± 1 11.5 ± 0.6
Pin 1 to 2 = 1.3K ± 13 Pin 2 to 3 = 620 ± 6.2 Pin 3 to 4 = 330 ± 3.3 Pin 1 to 4 = 2250 ±
Off-Machine Switch Specification Deactuate
Contact Position
Normally Open
----
A-B Normally Closed B-C Normally Open
----
A-B Normally Closed B-C Normally Open
122
123
36
67
66
65
CONN: 1B
26
CONN: 1A 124
135
¹ At room temperature unless otherwise noted.
294 kPa MIN (42.6 PSI MIN)
100
121
7
99
86 112
83
CONN: 12
96
CONN: 11 165
95 Related Electrical Service Manuals Title
36
Form Number
Alternator:
KENR5290
Starting Motor:
KENR5290
Engine Control:
KENR5429
M300D Electronic Systems:
UENR1770
M300D Monitoring Systems:
UENR1771
97
46 94 93
16
18
17
72
32
CONN: 47 19
HAMMER VALVE ONLY
21
20
31
137
4
133
30
71 88
CONN: 1A / 1B
109 MAIN HYDRUALIC CONTROL
ENGINE AND PUMP COMPARTMENT
Component Part Number
325-AG135 PK-14
CAB LH REAR VIEW
76
Dozer Blade Front / Rear Locks Left / Right Front and Rear Stabilizers MH Dozer Front Lock Joystick Steering Protection
Hydraulic Oil Clog Pressure
CONN: 56
34.9
250 ± 50 kPa and Up (36 ± 7 psi and Up)
1
Part Number: for Connector Plug
5
HYDRUALIC CAB RISER 17.6 ± 0.6
8000 ± 500 KpA and Down 1160 ± 72.5 psi )
CONN: 57
L-C12 3E-5179
Harness Connector Serialization Code: The "C" stands for "Connector" and the number indicates which connector in the harness (C1, C2, C3, ...).
145
Resistance (Ohms)¹
Actuate
L-C12 3E-5179
AG-C4 111-7898
CONN: 22
MACHINE LH REAR VIEW
65.9 ± 3.6
337-5788
75
Harness Identification Letter(s): (A, B, C, ..., AA, AB, AC, ...)
2
CONN: 41
Travel Lock Magnet Boom Float Boom Float Down Heavy Lift Fan Reverse Implement Lock Oscillating Axle Swing Brake Transmission Gear Shift 1,2
Brake Oil Pressure
CONN: 23
CONN: 54
CONN: 46
Solenoid:
337-5776
Wire, Cable, or Harness Assembly Identification: Includes Harness Identification Letters and Harness Connector Serialization Codes (see sample).
CONN: 36
CONN: 24
129-4508
309-5769
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.
CONN: 16
A/C Clutch
490 ± 49kPa (71 PSI ± 7.1 PSI)
119
Harness and Wire Symbols
CONN: 27
Component Description
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.
CONN: 21
CONN: 26
Solenoid:
Main Pump Pressure Swing Pump Pressure Boom Down Pilot
CONN: 59
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.
CONN: 15
CONN: 34
106-5122
Function
CAB BOTTOM VIEW
CONN: 48
81
Resistor, Sender and Solenoid Specifications
Part No.
Circuit Breaker Symbol
Flow Symbol
Fuse: A component in an electrical circuit that will open the circuit if too much current flows through it.
The connectors shown in this chart are for harness to harness connectors. Connectors that join a harness to a component are generally located at or near the component. See the Component Location Chart.
Part No.
Level Symbol
Symbols and Definitions
T
CONN 21
Temperature Symbol
CONN: 7 117 STANDARD UNDERCARRIAGE
FRONT DOZER BLADE OPTION
Wire Gauge Wire Color
(Dimensions: 56 inches x 35 inches)
Machine Location
42 Page,
Component
UENR1270-01 VOL 1 of 2
Schematic Location