Schematic Location
Component Location
Actuator - Engine Gov
A-9
Machine Location 1
Resistor - Timer Relay
E-7
Air Inlet Heater
C-8
2
Sender - Hydraulic Oil Temp
A-5
12
Alarm - Travel
G-9
3
Sender - Air Inlet Heater Coolant Temp
C-9
2
Alternator
B-8
4
Sender - Coolant Temperature
C-8
2
Assembly - Terminal Block
F-8
D
Sensor - Fuel Level
A-5
13
I-8,H-8
5
Sensor - Pump Discharge Press
B-8
14
Breaker - Alternator
I-8
D
Sensor - Sun Load
F-1
E
Breaker - Main
I-8
D
Solenoid - A/C Clutch
C-9
15
Control - Engine/Pump
F-2
C
Solenoid - Eng/Pump Control
A-7
16
111
Controller - Wiper/Washer
E-1
A
Solenoid - Engine Shutdown
B-9
17
112
PU
Main Power Relay Output
578
BU
Lower Washer SW
Converter - Voltage
C-5
A
Solenoid - Fine Swing
E-7
18
113
OR
Opr Mon Panel B (+) Switched
590
GY
Wiper SW To Wiper Controller
Diode
G-7
D
Solenoid - Hydraulic Lock
I-1
A
114
RD
Warning Horn Relay (Forward)
592
BU
DC/DC Converter Power Output
Diode - Main Relay
H-7
D
Solenoid - Level Finish
A-7
16
115
PK
Cab/Chassis Lamp Relay
A513
RD
DC/DC Converter Memory Output
GY
Wiper Relay
A571
PU
Aux Ckt 1
Batteries - 12VDC
Component
Schematic Location
Wire Description
Machine Location D
Component
Wire Number
Wire Color
Wire Number
Wire Color
101
RD
Bat (+)
513
OR
A/C Compressor/Refrigerant Pressure SW
103
RD
Dome Lamp
519
PK
A/C Unit To Refrigerant Press SW
105
RD
Key Sw
546
BU
Aux Hyd - Rotate CW
107
RD
Engine Shutdown
547
OR
Aux Hyd - Rotate CCW
108
BU
Aux Ckt
548
GY
Aux Hyd - Open
109
RD
Alt Output (+) Term.
549
PK
Aux Hyd - Close
RD
Timer Relay Out 1 To Fuse
576
PK
Lower Wiper SW
Description Power Circuits
Description Accessory Circuits (Continued)
I-4,5,6
B
Solenoid - Start Aid
H-9
19
118
Ground - Cab
B-5
6
Solenoid - Swing Brake
E-7
18
120
YL
Converter
A572
PK
Aux Ckt 2
Ground - Cab
E-1
E
Solenoid - Travel Speed
A-7
16
123
WH
Aux Ckt
A579
OR
Upper Wiper Motor
Ground - Chassis
A-3
7
Solenoid - Trenching
A-7
16
A/C
A586
OR
Washer SW To Washer Controller
Switch - Air Cleaner Flow
H-9
20
GN
A-9
8
124
Ground - Chassis Ground - Chassis
I-8
D
Switch - Aux Hydraulic Pressure
H-3
B
129
BU
Lighter
A588
GN
Hyd Lock Sol Relay To Hyd Lock Sol
Ground - Platform
G-2
B
Switch - Backup EPR Valve
E-5
C
140
BU
Aux Ckt
C537
GN
Sun Load Sensor (+)
Ground - Platform
H-1
9
Switch - Backup Governor
D-5
C
147
PU
Fine Swing Sol
C538
OR
Sun Load Sensor (-)
Ground - Relay Panel
H-8
D
Switch - Boom Raise Pressure
D-8
18
149
PU
Boom Lamp Relay
Ground Strap - Chassis to Platform
I-6
10
Switch - Coolant Level
H-9
19
150
RD
Hyd Lock Sol Relay
607
PK
Flood Lamp - Front
Ground Strap - Chassis to Disconnect SW
I-8
D
Switch - Disconnect
I-8
D
151
GN
Neutral Start SW
615
YL
Cab Flood Lamp
Horn
A-2
7
Switch - Engine Oil Level
A-8
1
152
BU
Lower Wiper SW
616
BU
Boom Flood Lamp
Lighter
E-1
E
Switch - Engine Oil Press
B-9
15
154
RD
Neutral Start Relay
Meter - Service
F-1
E
Switch - Fine Swing Control
D-4
C
168
RD
Aux Ckt
763
BU
Travel Speed Sol
Monitor
F-1
E
Switch - Horn
I-1
B
172
RD
Engine Governor Actuator
786
GN
Boom Lamp Relay To Boom Lamp SW
Motor - Lower Washer
I-9
D
Switch - Hydraulic Oil Filter
A-5
12
177
RD
Main Breaker
788
YL
Eng Speed Sensor (+)
Motor - Lower Wiper
H-1
9
Switch - Hydraulic Oil Level
A-5
12
180
GN
Aux Ckt
791
PK
Chassis Lamp Relay To Chassis Lamp SW
Motor - Starter
A-9
8
Switch - Implement Pressure
D-8
18
185
YL
Backup EPR Valve SW
A718
PU
AIH Coolant Temp Sender
Motor - Upper Washer
I-9
D
Switch - Key
F-3
C
189
RD
Timer Relay Out 2 To Fuse
A755
PK
Throttle Pos SW #1
Motor - Upper Wiper
C-5
9
Switch - Lower Washer
D-4
C
191
WH
Aux Ckt
A756
BU
Throttle Pos SW #2
Pickup - Engine Speed
B-9
11
Switch - Lower Wiper
D-3
C
Throttle Pos SW #3
Switch - Neutral Start Limit
I-1
B
GY
C-6,I-3
A
A757
Relay - Boom Lamp
I-7
D
Switch - One Touch Low Idle
F-2
C
Relay - Cab/Chassis Lamp
I-7
D
Switch - Refrigerant Low Press
C-9
15
Relay - Heater
F-7
D
Switch - Start Aid
D-5
C
Relay - Horn
I-7
D
Switch - Start Aid Coolant Temp
B-9
4
Relay - Hydraulic Lock Solenoid
I-7
D
Switch - Suction Line Shutoff Limit
A-6
12
Relay - Main
G-7
D
Switch - Throttle Position
E-3
C
Relay - Neutral Start
F-7
D
Switch - Travel Pressure
D-8
18
Relay - Start
F-8
D
Switch Panel
F-2
C
Relay - Timer
E-7
D
Unit - A/C, Heater
G-5
Resistor - Backup
I-8
D
Unit - Air Inlet Heater Control
I-7
Fuses
Radio - 12VDC
Control Circuits
Ground Circuits 200
BK
Main Chassis
A758
BR
Throttle Pos SW #4
201
BK
Operator Monitor Panel
A761
PU
Eng Governor Actuator Feedback
235
BK
Engine Pump Control
A762
PU
Eng Speed Sensor (-)
A768
BU
Pump Control Sol To Backup EPR Valve SW
Basic Machine Circuits 301
BU
Starter No. 1 Sol
A769
GY
Pump Control Sol To Backup EPR Valve SW
304
WH
Starter Relay No. 1 Output
A770
PK
Pump Control SW To Backup Resistor
306
GN
Starter Relay Coil
A771
PU
Implement Press SW
307
OR
Key SW To Neutral Start Relay
F771
OR
Gov Actuator (B)
21
308
YL
Main Power Relay Coil
F772
WH
Gov Actuator (A)
D
309
GY
Alternator Regulator Terminal
F773
OR
Eng Governor Actuator Accel
310
PU
Start Aid SW To Start Aid Sol
F774
WH
Eng Governor Actuator Decel
A = Located inside of cab. B = Located inside of left console.
311
WH
Start Aid Sol To Temp SW
J704
WH
Hyd Lock Sol Relay
320
OR
Horn Relay Coil To Horn SW
877
YL
Heater Relay To Air Inlet Heater
321
BR
Travel Alarm
961
BR
Aux Ckt
322
GY
Warning Horn (Forward)
K904
GN
Pump Discharge Press Sensor (Signal)
326
RD
Key SW "C" Terminal To Eng Shutdown Sol
K905
RD
Fuse To Eng Pump Control
386
PK
Neutral Start Relay
K906
GN
Swing Brake Sol To Backup EPR Valve SW
K907
BU
Backup EPR Valve SW To Eng/Pump Cont
D = Located around relay panel. E = Located in dash.
Monitoring Circuits 403
GN
Alternator (R) Term.
K909
BU
Backup Gov SW
405
GY
Opr Mon Oil Press. (Low Setting)
K911
PK
Eng/Pump Controller RS485 (+)
412
BU
Opr Mon Coolant Level
K912
GN
Eng/Pump Controller RS485 (-)
430
BU
Opr Mon Air Cleaner
K915
GN
Fine Swing SW To Eng/Pump Controller
487
OR
Opr Mon Hyd Oil Filter
K997
BU
Eng/Pump Controller To Monitor
491
PK
Hyd Oil Temp Sender
L908
OR
Controller RS-232C TX
492
GY
Coolant Temp Sensor
L909
BU
Controller RS-232C RX
495
GN
Fuel Level Sensor
L968
OR
Eng/Pump Controller To Backup EPR Valve
496
WH
Opr Mon Hyd Oil Level
L969
WH
Eng/Pump Controller To Backup EPR Valve
A495
GY
AIH Cont Unit (Regulator)
L970
GY
Aux Hyd Press SW
C468
BU
Engine Oil Level
L971
GN
Travel Press SW
L972
BU
Low Idle SW
Accessory Circuits
19
20
5
3
21
6
A
D
C
10
4
15
B 9
T
Pressure Symbol
Normally open switch that will close with an increase of a specific condition (temp-press-etc.). The circle indicates that the component has screw terminals and a wire can be disconnected from it. Normally closed switch that will open with an increase of a specific condition. No circle indicates that the wire cannot be disconnected from the component. This indicates that the component has a wire connected to it that is connected to ground. 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.
501
GN
Wiper - Front (Low)
L973
GN
Fine Swing SW To Fine Swing Sol
506
PU
Washer - Front
L974
GN
Boom Raise Press SW
508
PU
Radio Speaker - Left
L975
PK
Start Aid Cont Indicator
509
WH
Radio Speaker - Left (Common)
L977
YL
Level Finish Sol
511
BR
Radio Speaker - Right
L978
GY
Trenching Sol
512
GN
Radio Speaker - Right (Common)
322B L Excavator Electrical System
1
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.
1YS1-UP
Harness And Wire Symbols Pin
Single Wire Connector
1 2
Resistor, Sender and Solenoid Specifications
Part No.
Component Description
3E-6332
6 A
17 19
14 1
11
2
4
20 12
8
15 16
D
3
5
21 18 10
B
13
C
E 9
7
Resistor - Timer Relay
8C-3663
Solenoid - Engine Shutdown
102-8015
Resistor - Backup
Machine Harness Connector And Component Locations
Typical representation of a Deutsch connector. The plug contains all sockets and the receptacle contains all pins.
1 2
Typical representation of a Sure-Seal connector. The plug and receptacle contain both pins and sockets.
Machine Location
47 ± 4.7 Unlatch Coil - (10.30 ± 1.03)
Midpoint
CONN 1
A-9
1
CONN 2
F-9
D
CONN 3
F-9
D
CONN 4
G-9
D
CONN 5
G-9
D
CONN 6
G-8
D
CONN 7
G-8
D
CONN 8
G-8
D
Part No.
CONN 9
F-8
D
CONN 10
C-6
A
3E-6449
CONN 11
C-5
A
CONN 12
C-5
A
CONN 13
C-4
A
CONN 14
F-5
C
CONN 15
F-5
C
CONN 16
F-5
C
CONN 17
F-5
C
CONN 18
H-5
B
CONN 19
H-5
B
CONN 20
H-4
B
CONN 21
H-4
B
CONN 22
H-4
B
CONN 23
H-4
B
CONN 24
F-4
C
CONN 25
F-4
C
CONN 26
F-4
C
CONN 27
F-4
C
CONN 28
A-3
13
CONN 29
B-3
7
CONN 30
C-3
A
CONN 31
H-3
B
CONN 32
H-3
B
CONN 33
D-2
C
41.0 ± 2.05 8.0 + 1.0 8.0 - 0.5 33.8 ± 2.0 83.5 ± 1.5
111-9916
Solenoid - Engine/Pump Control
11.7 ± 1.2
116-3526
Solenoid - Fine Swing
34.5 ± 0.5
Solenoid - Level Finish
32.0 ± 3.2
Solenoid - Trenching Solenoid - Swing Brake
32.0 ± 3.2
Solenoid - Travel Speed
125-4812
Sender - AIH Coolant Temp
134-3998
2.53
Solenoid - A/C Clutch
17.6 ± 0.6
¹ At room temperature unless otherwise noted.
3E-6455 106-0179 106-0180
Function
Engine Oil Pressure Implement Pressure Travel Pressure Boom Raise Pressure
106-0181
Hydraulic Pressure
109-9330
Air Cleaner
114-5333
Off Machine Switch Specification
Start Aid Coolant Temperature
A/C Pressure Switch
Contact Position
Real Time Error Codes Code
Description of Problems
1301
Engine oil pressure is too low.
1302
Engine coolant temperature is too high.
1303
Hydraulic oil temperature is too high.
1304
Air filter is clogged.
1305
Battery voltage is not normal.
2201
Governor actuator feedback sensor circuit is open or shorted to battery voltage.
2202
Governor actuator feedback sensor circuit is shorted to body ground.
2301
Governor actuator feedback signal is not stable.
2302
Governor actuator feedback signal deviates.
2303
Governor actuator does not move.
2304
Calibration data error.
3201
Monitor RAM is not normal.
4101
Electric power supply to the controller is too much (43 volts).
4102
Over-current in proportional reducing valve.
4103
Proportional reducing valve circuit is open.
4105
Over-current in digital output (trenching solenoid).
4106
Over-current in digital output (fine control solenoid).
4107
Over-current in digital output (travel speed change solenoid).
4108
Over-current in digital output (travel alarm).
Actuate
Deactuate
38 ± 3° C
27° C MIN
(100 ± 5° F)
(80.6° F MIN)
90 ± 21 kPa
70 ± 21 kPa
(13 ± 3.0 psi)
(10 ± 3.0 psi)
A-B, Normally Open ² A-C, Normally Closed ²
1520 ± 98 kPa
1127 kPa MIN
Normally Open ²
410A
Over-current in digital output (swing brake solenoid).
(177.67 ± 14.21 psi)
(128.92 psi MIN)
4201
Engine speed is not normal.
2646.00 ± 196 kPa
2156.00 ± 196 kPa
Normally Open ²
4202
Engine coolant temperature sensor is shorted to body ground.
(383.77 ± 28.43 psi)
(383.77 ± 28.43 psi)
4203
Hydraulic oil temperature sensor is shorted to body ground.
490 ± 49 kPa
290 kPa MIN
4204
PWM sensor of pump delivery pressure is shorted to body ground.
4207
PWM sensor of pump delivery pressure is open in circuit.
(71 ± 7 psi)
(42 psi MIN)
420A
Fuel sensor is shorted to body ground
635 ± 58 mm H 2O
-
420B
Fuel sensor is open or shorted to battery voltage.
275 to 1750 kPa ¹
-
420C
Electric power supply is to low (below 23 volts).
(40 to 255 psi)
-
420D
Electric power supply is to high (above 32 volts).
420E
Engine speed dial is not in one of the 10 specified positions.
4301
Data mismatch 1 between alternator and speed sensor (alternator is abnormal).
4302
Data mismatch 2 between alternator and speed sensor (speed sensor is abnormal).
4303
Engine stalls.
A201
Monitor communication is not normal.
A202
Monitor takes too much time to respond to controller's signal.
A203
Communication is abnormal in controller.
Normally Closed ²
Normally Open ² Normally Open Normally Open ²
¹ With increasing pressure the closed condition can be maintained up to 2800 kPa (405 psi), with decreasing pressure the closed condition can be maintained down to 170 kPa (25 psi). ² Contact position at the contacts of the harness connector.
Related Electrical Service Manuals Title
Form Number
Alternator:
(9W-3043)
Electric Starting Motor:
(104-7040)
SENR4252
Consist:
6V-5720
SENR3581
Consist:
106-8557
SENR3859
Engine/Pump Control:
151-9373
SENR9291
Starting and Charging:
Printed in U.S.A.
Latch Coil - (1.55 ± 0.15)
Sensor - Fuel Level
121-1491
CONN 34 B-2 7 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.
200-BK-14
6134 to 7496
Sender - Hyd Oil temp
7Y-8242
Schematic Location
16
2
6.0
Sender - Coolant Temp
4I-5394
18
Connector Number
Plug
Resistance (Ohms)¹
Solenoid - Start Aid
105-9911
12
Receptacle
Wire Gauge
©2001 Caterpillar All Rights Reserved
Full
Connector Location
105-9344
Pin or Socket Number
121-1490
14
Circuit Number Identification
Fuse
AA 1
Ground Connection
E
13
Wire Color 325-PK-14
7
8
Socket
Component Part Number
Wire, Cable, or Harness Assembly Identification A
Empty
11
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
17 2
Circuit Breaker Symbol
Flow Symbol
Level Symbol
Temperature Symbol
Lighting Circuits
Machine locations are repeated for components located close together.
C = Located inside of right console.
Electrical Schematic Symbols And Definitions
SENR1679-01 APRIL 2001
SENR9292