Component Location
Component
Schematic
Location
Machine
Location
Component
Schematic
Location
Machine
Location
Actuator - Eng Governor A-9 1 Sensor - AIH Coolant Temp C-9 21
Air Heater C-8 2 Sensor - Fuel Level A-2 23
Alarm - Travel D-9 3 Sensor - Pump Discharge Press A-2 24
Alternator C-9 4 Sensor - Speed B-8 25
Battery F-9 6 Socket - 12V 5A H-5 A
Block - Terminal G-7 D Solenoid - Air Conditioner Clutch B-9 26
Breaker - Alt G-9 D Solenoid - Eng/Pump Cont A-7 F
Breaker - Main H-9 D Solenoid - Hydraulic Lock H-2 G
Control - Eng/Pump B-4, C-4 7 Solenoid - Level Finish A-7 F
Control - Power Window B-6 15 Solenoid - Quick Coupler #1 C-2, H-2 32
Control - Wiper E-2 A Solenoid - Quick Coupler #2 C-2, H-2 32
Converter J-2 8 Solenoid - Swing brake A-2 32
Converter - 12V 5A H-5 9 Solenoid - Travel Speed A-7 F
Fuse - Block J-4, 5, 6 C Solenoid - Trenching A-7 F
Indicator - Hydraulic Oil Filter B-7 E Switch - Quick Coupler E-5 B
Lighter - Cigar E-2 A Switch - Air Cleaner F-8 35
Meter - Service F-2 A Switch - Aux Hyd Pressure G-2 G
Monitor F-2 A Switch - Backup EPR Valve D-4 C
Motor - Lower Washer F-9 40 Switch - Backup Gov D-5 C
Motor - Lower Wiper G-2 G Switch - Boom Raise Press C-7 34
Motor - Starter A-9 14 Switch - Coolant Level E-9 36
Motor - Washer F-9 41 Switch - Disconnect G-9 D
Motor - Wiper E-2 A Switch - Engine Oil Level B-9 37
Panel - A/C Switch H-6 C Switch - Engine Oil Pressure B-9 38
Pump - Auto Lubrication E-9 16 Switch - Hammer Press G-2 G
Pump - Refueling B-2 17 Switch - Horn H-2 C
Relay - Air Heater H-7 D Switch - Hydraulic Oil Level B-7 E
Relay - Boom Lamp J-8 D Switch - Implement Swing Press B-7 32
Relay - Chassis/Cab Lamp J-9 D Switch - Key E-3 B
Relay - Demolition H-8 D Switch - Lower Washer E-4 B
Relay - Fan J-7 D Switch - Lower Wiper E-4 B
Relay - Horn J-9 D Switch - Neutral Start Limit H-2 C
Relay - Hydraulic Lock Solenoid J-8 D Switch - One Touch Low Idle F-3 B
Relay - Main H-8 D Switch - Panel F-3 B
Relay - Neutral Start J-8 D Switch - Power Window E-4 B
Relay - Refueling 1 B-2 18 Switch - Power Window Limit A-6, G-2 A
Relay - Refueling 2 B-2 19 Switch - Refrigerant Low Press E-9 39
Relay - Start H-7 D Switch - Refueling Level A-2 29
Relay - Start Cont J-7 D Switch - Refueling Start B-2 27
Relay - Timer J-7 D Switch - Refueling Stop B-3 28
Resistor - Backup J-9 D Switch - Seat Heater E-5 B
Resistor - Main Relay J-8 D Switch - Throttle Position E-3 B
Seat With Seat Heater F-5 20 Switch - Travel Press B-7 31
Sender - Coolant Temp C-9 22 Switch - Window Limit G-2 A
Sender - Hydraulic Oil Temp B-7 E Unit - Air Conditioner H-6 30
Sensor - A/C Photo E-3 A Unit - Air Heater Control J-7 D
Machine locations are repeated for components located close together.
A = Located inside of cab.
B = Located inside of right console.
C = Located inside of left console.
D = Located around relay panel.
E = Located around hydraulic oil tank.
F = Located around pilot manifold.
G = Located under platform.
Connector Location
Connector Number
Schematic
Location
Machine
Location
CONN 1 Service Connector H-9 D
CONN 2 G-8 D
CONN 3 G-8 D
CONN 4 G-8 D
CONN 5 D-8 D
CONN 6 D-8 D
CONN 7 D-8 D
CONN 8 D-8 D
CONN 9 D-7 D
CONN 10 D-7 D
CONN 11 G-7 D
CONN 12 G-7 D
CONN 13 F-6 G
CONN 14 E-6 G
CONN 15 E-6 G
CONN 16 E-6 G
CONN 17 D-6 G
CONN 18 B-6 A
CONN 19 B-6 A
CONN 20 B-5 A
CONN 21 B-5 A
CONN 22 B-5 G
CONN 23 B-5 G
CONN 24 C-5 G
CONN 25 C-5 11
CONN 26 E-5 B
CONN 27 12V 5A Socket H-5 A
CONN 28 H-5 30
CONN 29 H-5 G
CONN 30 H-4 G
CONN 31 H-4 G
CONN 32 H-4 G
CONN 33 A-3 23
CONN 34 H-2, H-3 G
CONN 35 J-2 30
CONN 36 C-2 12
CONN 37 B-2 17
CONN 38 B-2 28
CONN 39 B-2 27
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.
Related Electrical Service Manuals
Form Number
Engine/Pump Control:
RENR1998
Starting and Charging:
RENR1007
Title
Resistor, Sender and Solenoid Specifications
Part No. Component Description Resistance (Ohms)¹
4I-5394
Sender:
Hydraulic Oil Temperature
6815 ± 681
102-8016
Resistor:
Backup
47 ± 2.4
111-9916
Solenoid:
Engine / Pump Control
11.7 ± 1.2
121-1490 Solenoid:
Level Finish
Quick Coupler 1
Trenching
32.0 ± 3.2
121-1491 Solenoid:
Hydraulic Lock
Swing Brake
Quick Coupler 2
Travel Speed
32.0 ± 3.2
163-6616 Resistor: Main Relay
(1) 48 ± 2.4
(2) 48 ± 2.4
¹ At room temperature unless otherwise noted.
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 high (43 volts).
4102 Over-current in proportional reducing valve.
4103 Proportional reducing valve circuit is open.
4104 Spare solenoid 1 (digital output) over current.
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).
4109 Spare.
410A Over-current in digital output (swing brake solenoid).
410b Spare solenoid 2.
4201 Engine speed is not normal.
4202 Engine coolant temperature sensor is shorted to body ground.
4203 Hydraulic oil temperature sensor is shorted to body ground.
4204 PWM sensor of pump delivery pressure is shorted to body ground.
4205 Spare PWM sensor 1 is shorted to body ground.
4206 Spare PWM sensor 2 is shorted to body ground.
4207 PWM sensor of pump delivery pressure is open in circuit.
4208 Spare PWM sensor 1 circuit is open.
4209 Spare PWM sensor 2 circuit is open.
420A Fuel sensor is shorted to body ground.
420b Fuel sensor is open or shorted to battery voltage.
420C Electric power supply is too low (below 23 volts).
420D Electric power supply is too 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.
Real Time Error Codes
Off Machine Switch Specification
Part No. Function Actuate Deactuate Contact Position
106-0179
Implement Pressure
Travel Pressure
1520 ± 98 kPa
(220.4 ± 14 psi)
1127 kPa MIN
(163.5 psi MIN)
Normally Open
106-0180 Boom Raise Pressure
2646 ± 196 kPa
(383.8 ± 28.4 psi)
2156 ± 196 kPa
(312.7 ± 28.4 psi)
Normally Open
106-0181
Aux Hydraulic Pressure
Boom Raise Pressure
Crush Pressure 1 and 2
Hammer Pressure
490 ± 49 kPa
(71.1 ± 7.1 psi)
290 kPa MIN
(42.1 psi MIN)
Normally Open
Wire Description
Wire
Number
Wire
Color
Description
Wire
Number
Wire
Color
Description
Power Circuits Accessory Circuits (Continued)
101 RD Battery (+) 578 BU Washer - Aux
103 YL Dome Lamp / Monitor / Radio Back Up 590 GY Wiper SW To Intermittent Module
105 BR Key Sw 592 BU DC/DC Converter Power Output
109 OR Alt Output (+) Term. A513 RD DC/DC Converter Memory Output
111 YL Timer Relay To Engine/Pump Control A537 PK Seat Heater (Resistive Element In Cushion)
112 PU Main Relay Output A579 OR Wiper Motor +
113 OR Radio / Switch Panel A580 BR Wiper Motor -
114 GN Horn Relay A581 GN Wiper Motor Raise
115 PK Cab/Chassis Lamp Relay A582 PU Wiper Motor Stop
116 BR Fan Relay Output A583 YL Power Window Interlock To Wiper Cont
118 GY Wiper Control / Washer A584 BU Front Window Limit SW To Wiper Cont
120 YL 24V to 12V Converter (Input and Memory) A586 OR Wiper SW To Wiper Cont
124 GN Air Conditioner / Heater A587 YL Power Window Cont To Safety Sol Relay
129 BU Cigar Lighter A588 GN Safety Sol Relay To Sol
135 BU 24V to 12V Converter (Output) A589 OR Power Window Up
140 BU Auto Lubrication Pump A590 BU Power Window Down
147 PU Quick Cpler Sw / Seat Htr Sw / Crsh Sol / Atchs A591 PU Rear Window Limit SW
149 PU Boom Lamp Relay C537 GN A/C Photo Sensor + Sig
150 OR Hyd Lock Sol Relay / Neutral Start Limit Sw C538 OR A/C Photo Sensor - Sig
151 GN Neutral Start Limit Sw To Hyd Lock Sol Relay Lighting Circuits
152 BU Lower Wiper Motor / Lower Washer Switch 607 PK Flood Lamp - Front
154 WH Neut Start Switch To Neut Start Relay 615 YL Cab Flood Lamp/Rops
168 GN Hyd Oil Filter Ind / Refueling Relays 1 and 2 616 BU Bucket Flood Lamp/Boom Flood Lamp
172 GN Engine Governor Actuator Control Circuits
175 RD Fan 763 BU Torque Converter SW
176 OR Aux Ckt 780 PU Quick Coupler Sw to Quick Coupler Solenoid 1
177 OR Main Breaker Output 786 GN Eng Speed Cont - Hi Press SW
180 GN Aux Ckt 788 YL Eng Speed (+)
185 YL Backup EPR Valve Sw 791 PK Eng Speed Cont - Lo Sol
189 WH Timer Relay Output #2 A718 PU Start Aid Coolant Sensor Signal
191 WH Power Window (Switch and Control) A755 PK Throttle SW #1
Ground Circuits A756 BU Throttle SW #2
200 BK Main Chassis A757 GY Throttle SW #3
201 BK Operator Monitor Return A758 BR Throttle SW #4
235 BK Electronic Pump Ctrl Gnd A761 PU Governor Actuator Feedback To E/P ECM
Basic Machine Circuits A762 PU Eng Speed (-)
304 WH Starter Relay No. 1 Output A768 BU Pump Control Valve #1 (+)
306 GN Starter Relay Coil To Neut Start SW A769 GY Pump Control Valve #2 (-)
307 OR Key SW To Neut Start SW A770 PK Electronic Pump Control Bypass SW To Resistor
308 YL Main Power Relay Coil / A771 PU Float SW
309 GY Alt Regulator Term. F771 OR Backup SW
310 PU Start Aid SW To Start Aid Sol F772 WH Backup SW
320 OR Horn Relay Coil To SW F773 OR Governor Accel
321 BR Bckp Alarm Lamp Travel Alarm F774 WH Governor Decel
322 GY Warning Horn (Forward) J703 PK Alt Pulse Sig To Anti-Start Relay (was D746 PK)
323 WH Fuel Pump Power K785 GN Quick Coupler Sw to Quick Coupler Solenoid 2
325 PK Fuel Pump Relay Cut-Out 877 YL Glow Plug Magnetic SW To Glow Plug
330 YL Neut Start Relay Coil 954 GN Hammer SW A
365 YL Fuel Pump Relay To Switch G973 OR Boom Raise Press SW to Crush Press SW
Monitoring Circuits G974 WH Crush Sol to Demolition Relay
403 GN Engine/Pump Cntrl To Alternator (P) Term. G975 YL Crush Press SW to Demolition Relay
405 GY Engine/Pump Cntrl To Oil Pressure Sw K904 GN Pump Discharge - Signal
412 BU Engine/Pump Cntrl To Coolant Level Sw K905 BU Pump Discharge - +B
430 BU Engine/Pump Cntrl To Air Filter Sw K906 GN Swing Brake Sol - Signal
487 OR Engine/Pump Cntrl To Hyd Oil Filter Indicator K907 BU Swing Brake Sol - +B
491 PK Engine/Pump Cntrl To Hyd Oil Temp Sender K909 BU Backup SW - +B
492 GY Engine/Pump Cntrl To Coolant Temp Sender K911 PK E/P Controller - RS485 (+)
495 GN Engine/Pump Cntrl To Fuel Level Sensor K912 GN E/P Controller - RS485 (-)
496 WH Engine/Pump Cntrl To Hyd Oil Level Sw K997 BU +V Sensor
C468 BU Engine/Pump Cntrl To Engine Oil Level Sw L908 OR Controller RS-232C Tx
Accessory Circuits L909 BU Controller RS-232C Rx
501 GN Wiper - Front (Low) L968 OR Electronic Pump Control Ps Valve (-)
506 PU Washer - Front L969 WH Electronic Pump Control Ps Valve (+)
508 PU Radio Speaker - Left L970 GY Engine/Pump Control To Switch Common
509 WH Radio Speaker - Left (Common) L971 GN Engine/Pump Control To Travel Pressure Sw
511 BR Radio Speaker - Right L972 BU Engine/Pump Control To Low Idle SW
512 GN Radio Speaker - Right (Common) L974 GN Engine/Pump Cntrl To Boom Raise Press Sw
513 OR A/C Compressor/Refrigerant Pressure SW L975 PK Engine/Pump Control To AIH Indicator
519 PK Thermostat To Refrigerant Press. SW L976 GN Excavator Fuel Pump Switch
530 OR Washer Sw To Wiper Control L977 YL Trenching Sol
575 YL Wiper - Aux (Park) L978 GY Level Finish Sol
576 PK Wiper - Aux (Low)
A
3
4
5
6
8
9
10
11
12
14
15
13
16
B
C
D
E
1
2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
37
35
34
36
38
7
F
39
40
41
G
3
4
5
6
8
9
10
11
12
14
15
13
16
B
C
D
E
1
2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
37
35
34
36
38
7
F
39
40 41
A
G
10
Machine Harness And Component Locations
T
Normally open switch that will close with an increase of a specific condition (temp-press-etc.).
Normally open switch that is closed due to an applied condition, and will open again with a
specific decrease in that condition.
Normally closed switch that will open with an increase of a specific condition.
Normally closed switch that is open due to an applied condition, and will close again
with a specific decrease in that condition.
The circle indicates that the component has screw terminals and a wire can be disconnected
from it.
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.
Electrical Schematic Symbols And Definitions
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
A AA
2
A AA
1
2
325-PK-14
C
A
325-PK-14
200-BK-14
T
FUSE - A component in an electrical circuit that will open the circuit if too much current flows
through it.
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.
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.
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.
CIRCUIT BREAKER (C/B) - A component in an electrical circuit that will open the circuit if too
much current flows through it. This does not destroy the circuit breaker and it can be reset to
become part of the circuit again.
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.
Harness And Wire Electrical Schematic Symbols
Socket
Pin
Pin or Socket
Number
Wire, Cable, or Harness
Assembly Identification
Single Wire
Connector
Circuit Number
Identification
Wire
Gauge
Wire
Color
Plug
Receptacle
9X-1123
Component
Part Number
Electrical Schematic Symbols And Definitions
1
1
1
2
2
Typical representation of a
Sure-Seal connector. The
plugand receptacle contain
both pins and sockets.
Typical representation of a
Deutsch connector. The
plug contains all sockets
and the receptacle contains
all pins.
MAGNETIC LATCH SOLENOID - A magnetic latch solenoid is an electrical component that is
activated by electricity and held latch 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.
SENR9236-01
April 2000
311B and 312B Excavator
Electrical System
8GR1-UP
8HR1-UP
8JR1-UP
9GR1-UP
9HR1-UP
9MR1-UP
2LS1-UP
2MS1-UP
2NS1-UP
3ES1-UP
3FS1-UP
©
2000 Caterpillar
All Rights Reserved
Printed in U.S.A.
509-WH-18
512-GN-18
511-BR-18
508-PU-18
200-BK-18
103-RD-18
615-YL-18
113-OR-18
CONN 39
9 8 7
G
J
H
11
12
1
2
3
4
5
6
7
8
9
10
12
11
10
9
8
7
6
5
4
3
2
1
PK
2
OR
3
200-BK
140-BU
6
5
4
2
1
140-BU
1
200-BK
F
E
D
615-YL
615-YL-18
615-YL-18
615-YL-18
112-PU-6
172-RD-18
189-RD
320-OR-18
154-RD-18
151-GN-18
150-RD-18
114-RD-18
168-RD-14
115-PK-14
149-PU
140-BU
177-RD-14
177-RD-14
111-RD-14
615-YL-18
519-PK-18
308-YL-18
307-OR-18
578-BU-18
K906-GN-18
F773-OR-18
F774-WH-18
A770-PK-18
A769-GY-18
A768-BU-18
791-PK-18
786-GN-18
K909-BU-18
A771-PU-18
L978-GY-18
L974-GN-18
L977-YL-18
K997-BU-18
788-YL-18
A762-PU-18
763-BU-18
412-BU-18
C468-BU-18
321-BR-18
405-GY-18
492-GY-18
491-PK-18
495-GN-18
430-BU-18
496-WH-18
K904-GN-18
A761-PU-18
L971-GN-18
L975-PK-18
487-OR-18
615-YL
403-GN-18
506-PU-18
A587-YL-18
A
A
A
A
BB
A A
A
AIR CLEANER SW
109-9330
L975-PK-18
150-RD-18
615-YL
111-RD-14
177-RD-14
177-RD-14
151-GN-18
112-PU-6
149-PU
115-PK-14
114-RD-18
154-RD-18
320-OR-18
307-OR-18
308-YL-18
786-GN-18
791-PK-18
A770-PK-18
A588-GN-18
A587-YL-18
K909-BU-18
189-RD
172-RD-18
403-GN-18
491-PK-18
496-WH-18
495-GN-18
A769-GY-18
788-YL-18
A762-PU-18
C468-BU-18
405-GY-18
492-GY-18
321-BR-18
412-BU-18
519-PK-18
A768-BU-18
L971-GN-18
403-GN-18
168-RD-14
A769-GY-18
491-PK-18
496-WH-18
495-GN-18
403-GN-18
788-YL-18
A762-PU-18
C468-BU-18
168-RD-14
405-GY-18
492-GY-18
A768-BU-18
F774-WH-18
F773-OR-18
A761-PU-18
F774-WH-18
F773-OR-18
K904-GN-18
A761-PU-18
K904-GN-18
172-RD-18
K906-GN-18
K906-GN-18
L974-GN-18
A771-PU-18
L974-GN-18
L978-GY-18
L978-GY-18
L977-YL-18
L977-YL-18
763-BU-18
K997-BU-18
763-BU-18
A718-PU-18
A
B
MOTOR
K997-BU-18
506-PU-18
308-YL-18
309-GY-18
616-BU
322-GY-18
607-PK-18
877-YL-4
101-RD-4
578-BU-18
109-RD-6
513-OR-18
513-OR-18
BK/PK
BK
321-BR-18
519-PK-18
200-BK-18
506-PU-18
578-BU-18
200-BK-18
200-BK-18
200-BK-18
513-OR-18
200-BK-18
200-BK-18
412-BU-18
ATCH REFRIGERANT
LOW PRESS. SW
105-9344(NOTE A,NOTE F)
A771-PU-18
430-BU-18
200-BK-18
ATCH
TRAVEL ALARM
3E-7738
200-BK-18
513-OR-18
A
COOLANT
LEVEL SW
096-0744
MOTOR
513-OR-18
WASHER
7T-8890
ATCH
LOWER WASHER
7T-8890
487-OR-18
200-BK-18
321-BR-18
CC BB
AA
200-BK
200-BK-18
412-BU-18
200-BK-18
200-BK-18
506-PU-18
519-PK-18
487-OR-18
578-BU-18
140-BU
BATTERY
3T-5760
9X-3404(NOTE B)
200-BK-18
POS
NEG NEG
POS
L971-GN-18
304-WH-8
J703-PK-18
A
A
ON(KEY)
GROUND
2
1
ATCH AUTO
LUBRICATION PUMP
127-5264
200-BK
200-BK-18
RD-00RD-00BK-00
BK
WH
4
3
5
C
B
A
G
J
H
F
E
D
C
B
A
L974-GN-18
A769-GY-18
A768-BU-18
L978-GY-18
763-BU-18
L977-YL-18
487-OR-18
168-RD-18
491-PK-18
496-WH-18
172-RD-18
A761-PU-18
F773-OR-18
F774-WH-18
308-YL-18
K904-GN-18
K997-BU-18
308-YL-18
F774-WH-18
F773-OR-18
A761-PU-18
172-RD-18
L977-YL-18
763-BU-18
L978-GY-18
A768-BU-18
A769-GY-18
200-BK-6
109-RD-6
513-OR-18
J703-PK-18
403-GN-18
309-GY-18
492-GY-18
405-GY-18
304-WH-8
101-RD-4
C468-BU-18
A718-PU-18
AIR HEATER
5I-7746
B
2
1
B
A762-PU-18
877-YL-4
788-YL-18
200-BK-6
ENG SPEED
PICKUP
125-2966
788-YL-18
A762-PU-18
877-YL-4
K997-BU-18
200-BK-18
T
A718-PU-18
C468-BU-18
200-BK-18
AIH COOLANT
TEMP SENSOR
125-2982
B
2
1
200-BK-18
B
BB
B
B
B
RD-00
101-RD-4
PUMP DISCHARGE
PRESS. SENSOR
106-0178
SIGNAL
GROUND
+B
BK-18
BR-18
B
C
CHASSIS
B
GND
F/B
+B
ACCEL
200-BK-18
403-GN-18
109-RD-6
J703-PK-18
200-BK-18
513-OR-18
B
309-GY-18
YL-18
DECEL
6
BB
ENG GOV
ACTUATOR
120-0002
200-BK-18
B
KEY
ALTERNATOR
5I-8071(NOTE F)
(35A)
5I-8085(NOTE E)
(50A)
ENG OIL
LEVEL SW
111-4760
1
2
2
109-RD-6
1
200-BK-18
200-BK-18
200-BK-18
200-BK-18
172-RD-18
200-BK-6
B
200-BK-18
200-BK-18
A761-PU-18
C468-BU-18
F773-OR-18
200-BK-18
F774-WH-18
304-WH-8
405-GY-18
A718-PU-18
308-YL-18
T
COOLANT TEMP
SENDER
5I-7578
492-GY-18
492-GY-18
309-GY-18
405-GY-18
403-GN-18
200-BK-6
200-BK-18
J703-PK-18
STARTER
125-2988
L
E
B
P
R
ALT
K997-BU-18
B
200-BK-18
B
2
1
ENG OIL SW
5I-8005
AA
K904-GN-18
200-BK-18
513-OR-18
A
200-BK-18
ATCH A/C COMPR
CLUTCH SOL
117-6353(NOTE F)
154-0490(NOTE E)
MOTBAT
G
S
MOTOR
K904-GN-18
200-BK-18
200-BK-18
B
B
B
B
2
1
ENG/PUMP CONT
SOL
111-9916
LEVEL FINISH
SOL
121-1490
A768-BU-18
TRENCHING
SOL
121-1490
TRAVEL SPEED
SOL
121-1491
A769-GY-18
L978-GY-18
200-BK-18
763-BU-18
200-BK-18
L977-YL-18
200-BK-18
B
L971-GN-18
A771-PU-18
L974-GN-18
200-BK-18
200-BK-18
A771-PU-18
B
200-BK-18
B
SIGNAL
GROUND
200-BK-18
BOOM RAISE
PRESS. SW
106-0180
B
B
2
1
+B
A
168-RD-18
B
HYD OIL
FILTER
INDICATOR
116-3660
200-BK-18
200-BK-18
200-BK-18
B
L971-GN-18
IMPLEMENT
PRESS. SW
106-0179
491-PK-18
HYD OIL
TEMP SENDER
4I-5394
HYD OIL
LEVEL SW
111-4760
496-WH-18
C
T
B
200-BK-18
487-OR-18
A769-GY-18
A768-BU-18
200-BK-18
L978-GY-18
200-BK-18
763-BU-18
607-PK-18
322-GY-18
616-BU
200-BK-18
TRAVEL
PRESS. SW
106-0179
200-BK-18
L977-YL-18
K906-GN-18
168-RD-14
495-GN-18
Y/W
Y/G
B
G
R/L
200-BK
R
BR
120-YL
6 5 4
PLATFORM
PLATFORMCHASSIS
GROUND STRAP
7G-1060
200-BK-18
200-BK
200-BK-18
200-BK-14
519-PK-18
200-BK-14
615-YL-18
103-RD-18
103-RD-18
191-WH-14
191-WH-18
152-BU
152-BU-18
200-BK-18
113-OR-18
185-YL-18
105-RD-14
129-BU-18
118-GY
K905-RD-14
111-RD-14
177-RD-14
177-RD-14
140-BU
149-PU
115-PK-14
168-RD-14
114-RD-18
150-RD-18
151-GN-18
154-RD-18
320-OR-18
189-RD
172-RD-18
112-PU-6
200-BK
200-BK-18
103-RD-18
615-YL-18
509-WH-18
508-PU-18
511-BR-18
512-GN-18
576-PK-18
152-BU-18
575-YL-18
A588-GN-18
954-GN-18
L970-GY-18
152-BU-18
152-BU
191-WH-18
191-WH-14
103-RD-18
103-RD-18
103-RD-18
512-GN-18
511-BR-18
508-PU-18
509-WH-18
103-RD-18
615-YL-18
200-BK-18
200-BK
112-PU-14
172-RD-18
189-RD
320-OR-18
154-RD-18
151-GN-18
150-RD-18
114-RD-18
168-RD-14
115-PK-14
149-PU
140-BU
116-BR-14
177-RD-14
177-RD-14
112-PU-14
111-RD-14
103-RD-18
K905-RD-14
191-WH-14
200-BK-18
152-BU
118-GY
129-BU-18
200-BK-14
105-RD-14
175-RD-14
519-PK-18
151-GN-18
519-PK-18
124-GN-14
6
7
8
5
4
3
2
1
175-RD-14
615-YL-18
185-YL-18
120-YL
120-YL
200-BK
200-BK
135-BU
615-YL-18
FUSE
10A 9W-1442
15A 9W-1441
20A 9W-1446
112-PU-14
A AA
H HH
112-PU-14
113-OR-18
SWITCH PANEL
200-BK-14
113-OR-18
A
H
HHH
124-GN-14
124-GN-14
185-YL-18
12
150-RD-18
11
10
1
2
3
4
5
9
8
112-PU-14
150-RD-18
OPERATOR STATION
112-PU-14
15A
10A
10A
10A
10A
10A
20A
15A
191-WH-14
115-PK-14
120-YL
152-BU
140-BU
149-PU
124-GN-14
168-RD-14
HYD LOCK SOL
105-RD-14
129-BU-18
AUX CKT
103-RD-18
10A
10A
15A
15A
114-RD-18
177-RD-14
10A
LUBRICATOR
BOOM LAMP
REFUELING PUMP
KEY SW
DOME LAMP
116-BR-14
15A
HORN
320-OR-18
172-RD-18
154-RD-18
112-PU-14
177-RD-14
111-RD-14
189-RD-14
10A
A/C /HEATER
CIGAR LIGHTER
112-PU-14
115-PK-14
149-PU
113-OR-18
LOWER WASHER/WIPER
CONVERTER
200-BK-18
CAB/CHASSIS LAMP
PWR WINDOW
HYD LOCK SW
168-RD-14
105-RD-14
103-RD-18
C537-GN-18
114-RD-18
140-BU
124-GN-14
120-YL
113-OR-18
191-WH-14
152-BU
118-GY
129-BU-18
177-RD-14
K905-RD-14
177-RD-14 112-PU-14
E/P CONT
112-PU-14
15A
AUX CKT
112-PU-6
154-RD-18
151-GN-18
6
5
4
3
2
1
1
2
3
4
5
6
7
8
9
10
11
12
172-RD-18
ENG GOV
189-RD-14
WASHER/WIPER
118-GY
150-RD-18
185-YL-18
BACKUP
7
6
10A
112-PU-14
112-PU-14
111-RD-14
176-YL
180-GN
10A
10A
10A
10A
15A
320-OR-18
200-BK-18
C538-OR-18
200-BK
150-RD-18
10A
K905-RD-14
ATCH A/C UNIT
154-0523(NOTE F)
130-0250(NOTE E)
6
1
3
HEATER UNIT
151-9680(NOTE F)
139-7258(NOTE E)
4
5
2
1
2
A
X
4
6
3
X
ATCH
12V 5A
SOCKET
121-0987
ATCH 12V 5A
CONVERTER
119-1733
2
5
1
12V MEMORY
24V MEMORY
24V IN
GND
GND
12V OUT
120-YL
G
A
116-BR-14
168-RD-14
FUSE BASE
111-4812
111-RD-14
112-PU-14
112-PU-14
189-RD-14
K905-RD-14
185-YL-18
150-RD-18
172-RD-18
112-PU-14
112-PU-14
112-PU-14
177-RD-14
177-RD-14
114-RD-18
103-RD-18
105-RD-14
149-PU
140-BU
113-OR-18
118-GY
129-BU-18
124-GN-14
152-BU
120-YL
115-PK-14
191-WH-14
113-OR-18
112-PU-14
112-PU-14
116-BR-14
112-PU-14
RADIO
113-OR-18
512-GN-18
511-BR-18
509-WH-18
508-PU-18
K905-RD-14
129-BU-18
103-RD-18
118-GY
103-RD-18
191-WH-14
576-PK-18
575-YL-18
191-WH-18
152-BU
185-YL-18
105-RD-14
147-PU-18
113-OR-18
200-BK-18
K909-BU-18
A
A
7
8
1
6
5
4
3
2
200-BK-18
200-BK-14
200-BK-14
G
G
12
10
8
11
12
9
10
11
1
9
8
2
7
6
5
4
3
2
1
4
5
6
8
1
7
4
6
5
3
2
7
3
GA
G
235-BK-14
PLATFORM
A
A755-PK-18
A756-BU-18
A757-GY-18
A758-BR-18
308-YL-18
308-YL-18
307-OR-18
105-RD-14
590-GY-18
501-GN-18
A586-OR-18
590-GY-18
501-GN-18
A586-OR-18
A590-BU-18
A589-OR-18
308-YL-18
F771-OR-18
F772-WH-18
L969-WH-18
L968-OR-18
K907-BU-18
A755-PK-18
A756-BU-18
A757-GY-18
A758-BR-18
L972-BU-18
786-GN-18
791-PK-18
200-BK-18
113-OR-18
105-RD-14
185-YL-18
152-BU
530-OR-18
191-WH-18
575-YL-18
A768-BU-18
A769-GY-18
A770-PK-18
F774-WH-18
F773-OR-18
K906-GN-18
578-BU-18
307-OR-18
308-YL-18
113-OR-18
791-PK-18
786-GN-18
576-PK-18
575-YL-18
152-BU
578-BU-18
191-WH-18
A590-BU-18
A589-OR-18
A586-OR-18
501-GN-18
590-GY-18
A755-PK-18
A756-BU-18
A757-GY-18
A758-BR-18
105-RD-14
615-YL-18
307-OR-18
308-YL-18
308-YL-18
200-BK-18
200-BK-18
G
200-BK-18
200-BK-18
615-YL-18
F771-OR-18
F773-OR-18
F774-WH-18
F772-WH-18
K909-BU-18
K907-BU-18
A770-PK-18
L969-WH-18
L968-OR-18
200-BK-18
G
A769-GY-18
A768-BU-18
K906-GN-18
185-YL-18
200-BK-18
200-BK-18
576-PK-18
575-YL-18
152-BU-18
200-BK-18
615-YL-18
K909-BU-18
K907-BU-18
200-BK-18
L969-WH-18
A770-PK-18
L968-OR-18
152-BU-18
A769-GY-18
152-BU
A768-BU-18
A769-GY-18
578-BU-18
A768-BU-18
615-YL-18
615-YL-18
K906-GN-18
191-WH-18
185-YL-18
185-YL-18
L968-OR-18
A590-BU-18
200-BK-18
F771-OR-18
F773-OR-18
L969-WH-18
A589-OR-18
F774-WH-18
615-YL-18
615-YL-18
11
8
F772-WH-18
GG
5
A770-PK-18
786-GN-18
A589-OR-18
A590-BU-18
191-WH-18
K906-GN-18
2
12
10
K907-BU-18
9
185-YL-18
7
6
4
578-BU-18
3
1
185-YL-18
3
2
1
152-BU
575-YL-18
576-PK-18
200-BK-18
200-BK-18
BACKUP
EPR VALVE SW
114-0421
200-BK-18
200-BK-18
200-BK-18
GG
BACKUP
GOV SW
110-7884
K909-BU-18
200-BK-18
K909-BU-18
L972-BU-18
791-PK-18
113-OR-18
576-PK-18
L972-BU-18
ENG/PUMP CONT
119-9967(NOTE G)
119-9964(NOTE H)
3 2 1
9 8 7 6 5 4 3 2 1
A
113-OR-18
615-YL-18
103-RD-18
200-BK-18
508-PU-18
511-BR-18
512-GN-18
509-WH-18
3
1
8
2
5
4
6
7
ATCH
WINDOW LIMIT SW
117-6306 (NOTE C)
L L
WINDOW
LIMIT SW
124-3974 (NOTE D)
E
OPERATOR STATION
ATCH
CAB LAMP
153-2521
ATCH
CAB LAMP
5I-8250
140-0853
LL
200-BK-18
200-BK-18
200-BK
615-YL
DD
DD
200-BK
200-BK-18
A584-BU-18
615-YL
200-BK-18
A584-BU-18
615-YL
200-BK-18
615-YL-18
615-YL-18
113-OR-18
ATCH
AUX HYD
PRESS. SW
106-0181
ATCH
HAMMER
PRESS. SW
106-0181
L970-GY-18
954-GN-18
200-BK-18
200-BK-18
A
A
A
200-BK-18
L970-GY-18
954-GN-18
200-BK-18
200-BK-18
A588-GN-18
615-YL-18
200-BK-18
E
ATCH
AM/FM RADIO
153-2444
P
H
H
PLATFORM
A
200-BK-18
615-YL-18
575-YL-18
152-BU-18
113-OR-18
576-PK-18
103-RD-18
200-BK-18
508-PU-18
200-BK-18
509-WH-18
511-BR-18
512-GN-18
A588-GN-18
HYD LOCK SOL
121-1491
SPEAKER (+)
SPEAKER (-)
200-BK-18
BUCK UP
GND
SPEAKER (+)
ACC (+)
ILLUMI (+)
SPEAKER (-)
575-YL-18
200-BK-18
152-BU-18
320-OR-18
NEUTRAL START
LIMIT SW
111-4799
HORN SW
6I-5088
150-RD-18
ATCH RADIO FOR JAPAN
151-GN-18
154-RD-18
576-PK-18
2
1
ATCH
AM RADIO
116-0218
ATCH LOWER
WIPER MOTOR
113-3452
+
S
+1
-
MOTOR
5
4
3
2
1
OPERATOR STATION
129-BU-18
K911-PK-18
K997-BU-18
103-RD-18
K912-GN-18
615-YL-18
A/C PHOTO
SENSOR
113-3431 (NOTE J)
Y/G
Y/W
C537-GN-18
C538-OR-18
1
2
13
12
10
4
6
5
8
11
9
D
CAB
3
D
D
D
+
A586-OR-18
A580-BR
506-PU-18
A581-GN
A582-PU
200-BK-14
200-BK
200-BK-18
A586-OR-18
200-BK-18
118-GY
W.CCW
W.CW
REV
501-GN-18
STOP
200-BK-18
WIPER MOTOR
122-9603
GND
+B
L CHASSIS
L BOOM
WASH
W LOW
W INT(3)
G
G
G
G
200-BK-18
A758-BR-18
A757-GY-18
A756-BU-18
113-OR-18
791-PK-18
105-RD-14
786-GN-18
307-OR-18
200-BK-18
530-OR-18
308-YL-18
501-GN-18
SWITCH PANEL
153-2500
KEY SW
9G-7641
R
C
ONE TOUCH
LOW IDLE AND
PRESS. RAISE SW
6I-5088
6
S
B
OFF
ON
ST
590-GY-18
L972-BU-18
A755-PK-18 PK
BU
GN
308-YL-18
BR
BK
200-BK-18
S4
S3
S2
S1
COM
G
THROTTLE
POS SW
106-0107
WIPER CONT
155-7042
118-GY
A583-YL-18
GND
506-PU-18
INT (6)
201-BK-18
ACC
501-GN-18
WA+
A583-YL-18
403-GN-18
590-GY-18
403-GN-18
MONITOR
106-0172
A579-OR
615-YL-18
-
LOW
WIPER CUT
590-GY-18
SERVICE
METER
6T-7337
RISE.S
MOTOR
K912-GN-18
A584-BU-18
103-RD-18
K997-BU-18
DD
K911-PK-18
INT (3)
200-BK-18
GND
LIGHT
RS485-
+B
A584-BU-18
129-BU-18
MAIN
200-BK-14
200-BK
RS485+
201-BK-18
CIGAR
LIGHTER
9W-0335
200-BK-18
GY
PU
BR
RED
WHITE
ORANGE
YELLOW
PINK
ABBREV COLOR
BLACK
GRAY
PURPLE
BROWN
BK
PK
YL
OR
WH
RD
GN
BU
GREEN
BLUE
A584-BU-18
200-BK-18
200-BK-18
A584-BU-18
615-YL
200-BK-18
200-BK-18
NOTE D: NOT NECESSARY FOR ELECTRIC OPENABLE
WINDSHIELD.
NOTE C: USE WITH ELECTRIC OPENABLE WINDSHIELD.
2
1
NOTE T: USE WITH ALL ATTACHMENT OF X272,X275.
NOTE S: NOT USE WITH ALL ATTACHMENT.
(NOTE T)
AG
(NOTE T)
AG
L32
L32
L32
L31
L31
L31
L31
K785-GN-18
780-PU-18
147-PU-18
K785-GN-18
780-PU-18
147-PU-18
147-PU-18
AF
2
1
(NOTE T)
L32L33
147-PU-18
K785-GN-18
200-BK-18
780-PU-18
K785-GN-18
200-BK-18
200-BK-18
K785-GN-18
780-PU-18
780-PU-18
A
B
C
ANTENNA
200-BK-18
P
7
6
4
5
2
8
1
3
ATCH RADIO FOR OUTSIDE JAPAN
SPEAKER (-)
ILLUMI (+)
ACC (+)
SPEAKER (+)
GND
BUCK UP
SPEAKER (-)
SPEAKER (+)
512-GN-18
511-BR-18
509-WH-18
508-PU-18
200-BK-18
103-RD-18
113-OR-18
615-YL-18
P
ATCH
AM/FM RADIO
153-2445
ATCH A/C
SWITCH PANEL
119-6828(NOTE F)
139-7207(NOTE E)
HEATER SWITCH
PANEL
119-6826(NOTE F)
139-7261(NOTE E)
200-BK-14
200-BK-14
200-BK-14
200-BK-14
AF
(NOTE T)
AF
L33
AF
(NOTE T)
200-BK-18
200-BK-18
1
AG
(NOTE T)
ATCH QUICK
COUPLER SOL 1
121-1490(NOTE T)
2
1
2
ATCH QUICK
COUPLER SOL 2
121-1491(NOTE T)
AG
(NOTE T)
L31
200-BK-18
780-PU-18
K785-GN-18
200-BK-18
200-BK-18
K785-GN-18
780-PU-18
200-BK-18
200-BK-18
200-BK-18
AB
(NOTE R)
ATCH
MAIN RELAY
159-9108
(NOTE R)
ATCH
MAIN RELAY RESISTOR
163-6616 (NOTE R)
112-PU-18
MAIN RELAY
3T-0376
(NOTE P)
C (NOTE P)
AB(NOTE R)
C (NOTE P)
AB(NOTE R)
AE
AD
OR-18
BR-18
PK-18
200-BK-18
322-GY-18
200-BK
616-BU
AC
AB
(NOTE N)
(NOTE S)
(NOTE K)
1
2
L30
LL LL
LL
(NOTE N)
KK
(NOTE N)
JJ
(NOTE N)
(NOTE S)
1
LL
2
147-PU-18
JJ
K785-GN-18
L30
NOTE R: USE WITH COLD WEATHER FOR JAPAN.
200-BK-18
780-PU-18
147-PU-18
780-PU-18
K785-GN-18
147-PU-18
147-PU-18
200-BK-18
200-BK-18
JJ
(NOTE N)
(NOTE S)
ATCH QUICK
COUPLER SOL 1
121-1490(NOTE N)
(NOTE S)
2
1
2
ATCH QUICK
COUPLER SOL 2
121-1491(NOTE N)
(NOTE S)
JJ
(NOTE N)
(NOTE S)
1
G975-YL-18
G973-OR-18
L29
147-PU-18
147-PU-18
780-PU-18
KK
(NOTE N)
L30
L29
200-BK-18
C
B
A
200-BK-18
NOTE P: NOT USE WITH COLD WEATHER FOR JAPAN.
K785-GN-18
147-PU-18
147-PU-18
200-BK-18
1
2
3
4
5
T
GY-18
T
V
ATCH QUICK
COUPLER SW
150-6988(NOTE N)
5
2
6
4
6
3
1
Z(NOTE K)
Z
Z Z
W
W
Z
W
NOTE K: USE WITH X273.
Z
Y
X
ATCH CRUSH SOL
127-6845(NOTE K)
147-PU-18
G974-WH-18
1
2
L28
G974-WH-18
147-PU-18
G973-OR-18
1
2
147-PU-18
ATCH
BOOM RAISE
PRESS. SW
106-0181(NOTE K)
V
L28
L27
L26
L27
L26
147-PU-18
G973-OR-18
G974-WH-18
L27
G974-WH-18
G975-YL-18
G973-OR-18
G975-YL-18
ATCH DEMOLITION
RELAY
149-5050(NOTE K)
200-BK-18
1
1
2
KK
JJ
(NOTE S)
G975-YL-18
V
ATCH
CONVERTER
134-1346
G974-WH-18
L26
L26
L26
G975-YL-18
VV
TO RADIO
ATCH RADIO CONVERTER FOR OUTSIDE JAPAN
512-GN-18
509-WH-18
511-BR-18
508-PU-18
A513-RD-18
8
6
7
4
2
5
1
3
592-BU-18
GND
IGN
592-BU-18
A513-RD-18
200-BK-18
12V
MEM
530-OR-18
530-OR-18
WASH
530-OR-18
7
530-OR-18
24V
113-OR-18
A586-OR-18
W INT(6)
530-OR-18
530-OR-18
615-YL-18
A586-OR-18
177-RD-14
177-RD-14
175-RD-14
177-RD-14
177-RD-14
175-RD-14
175-RD-14
FAN
177-RD-14
177-RD-14
G973-OR-18
MM(NOTE E)
1
175-RD-14
177-RD-14
2
308-YL-18
200-BK-18
ATCH CRUSH
PRESS. SW 1
106-0181(NOTE K)
Y
(NOTE K)
G975-YL-18
2
1
1
2
ZZ
COMPONENTS ARE SHOWN INSTALLED ON A FULLY
OPERABLE MACHINE WITH THE KEY AND ENGINE OFF.
THIS SCHEMATIC IS FOR THE 311B/312B-HYD EXCAVATOR.
CC
BB
AA
CABLE AS.
XX
WIRE AS.
P
G973-OR-18
Y
ATCH CRUSH
PRESS. SW 2
106-0181(NOTE K)
116-BR-14
177-RD-14
L
K
J
H
G
E
D
C
B
DESCRIPTIONSYMBOL
CONNECTOR
ELECTRICAL CONNECTION
INTERNAL ELECTRICAL
CONNECTION TO SURFACE
OF COMPONENT
BLADE, SPADE, RING,
OR SCREW TERMINAL
CIRCUIT CONNECTED
CIRCUIT NOT CONNECTED
ATCH WIRE, CABLE,
COMPONENT
L#
CIRCUIT GROUPING
DESIGNATION
IDENT PART NO. LOC
HARNESS AS.
NOTE B: USE WITH COLD WEATHER.
308-YL-18
200-BK-18
N
WW
R
S
154-RD-18
307-OR-18
200-BK-18
NEUTRAL START
RELAY
149-5050
308-YL-18
306-GN-18
10
9
8
11
A
A770-PK-18
J703-PK-18
309-GY-18
403-GN-18
154-RD-18
307-OR-18
177-RD-14
189-RD
111-RD-14
L975-PK-18
151-GN-18
150-RD-18
A588-GN-18
A587-YL-18
A718-PU-18
791-PK-18
114-RD-18
322-GY-18
320-OR-18
786-GN-18
149-PU
616-BU
607-PK-18
115-PK-14
615-YL
200-BK-18
200-BK-18
200-BK-18
200-BK-18
200-BK-18
200-BK-18
200-BK-18
200-BK-18
310-PU-18
200-BK-18
403-GN-18
200-BK-18
309-GY-18
J703-PK-18
111-RD-14
189-RD
177-RD-14
116-BR-14
200-BK-18
K909-BU-18
177-RD-6
200-BK-18
307-OR-18
154-RD-18
L975-PK-18
200-BK-18
A718-PU-18
310-PU-18
200-BK-18
200-BK
INDICATOR
177-RD-14
177-RD-14
1
2
177-RD-14
177-RD-14
START RELAY
125-1302
112-PU-6
330-YL-18
616-BU
306-GN-18
607-PK-18
322-GY-18
149-PU
615-YL
154-RD-18
786-GN-18
791-PK-18
320-OR-18
114-RD-18
189-RD
115-PK-14
K909-BU-18
200-BK
A588-GN-18
150-RD-18
151-GN-18
111-RD-14
307-OR-18
308-YL-18
A587-YL-18
DISCONNECT SW
7N-0718
DD
ALT BREAKER
9S-0174
112-PU-6
308-YL-18
304-WH-8
OUT 1
OUT 2
+B
IN 1
GND
IN 2
C (NOTE P)
AB(NOTE R)
C (NOTE P)
AB(NOTE R)
A
C (NOTE P)
AB(NOTE R)
A
A
C (NOTE P)
AB(NOTE R)
B
B
A718-PU-18
RELAY PANEL
308-YL-18
6
5
4
3
2
1
BACKUP
RESISTOR
102-8016
10
HYD LOCK SOL
RELAY
149-5050
5
3
4
6
2
1
7
8
9
10
11
12
K909-BU-18
A718-PU-18
309-GY-18
616-BU
322-GY-18
607-PK-18
877-YL-4
109-RD-6
A587-YL-18
101-RD-6
2
8
9
3
CHASSIS
DD
200-BK
200-BK
A770-PK-18
A770-PK-18
K909-BU-18
K909-BU-18
A770-PK-18
304-WH-8
RELAY PANEL
200-BK-18
BK-00
4
1
149-PU
149-PU-18
307-OR-18
200-BK-18
111-RD-14
7
189-RD
177-RD-14
111-RD-14
200-BK-18
151-GN-18
K909-BU-18
A
TIMER RELAY
111-4870
150-RD-18
115-PK-18
101-RD-6
A588-GN-18
101-RD-4
791-PK-18
607-PK-18
615-YL
151-GN-18
150-RD-18
200-BK
12
CAB/CHASSIS
LAMP RELAY
149-5050
A588-GN-18
A587-YL-18
K909-BU-18
109-RD-6
6
115-PK-14
115-PK-14
189-RD
114-RD-18
5
4
5
60A
320-OR-18
791-PK-18
786-GN-18
786-GN-18
112-PU-6
154-RD-18
615-YL
200-BK-18
149-PU
BLOCK
121-1023
616-BU
6
3
12
2
1
7
11
8
9
HORN RELAY
149-5050
BOOM LAMP
RELAY
149-5050
10
A770-PK-18
322-GY-18
114-RD-18
177-RD-14
308-YL-18
308-YL-18
200-BK-18
177-RD-14
320-OR-18
114-RD-18
177-RD-14
A587-YL-18
A588-GN-18
177-RD-14
177-RD-14
177-RD-8
177-RD-14
177-RD-8
K909-BU-18
K909-BU-18
60A
101-RD-6
177-RD-6
MAIN BREAKER
9S-0174
116-BR-14
150-RD-18
151-GN-18
200-BK-18
616-BU
C (NOTE P)
AB(NOTE R)
SS(NOTE P)
AE(NOTE R)
200-BK-18
310-PU-18
306-GN-18
149-PU
786-GN-18
A718-PU-18
200-BK-18
310-PU-18
11
320-OR-18
322-GY-18
114-RD-18
308-YL-18
304-WH-8
3
1
2
309-GY-18
4
308-YL-18
7
200-BK-18
791-PK-18
HEATER
CONT UNIT
104-3204
J703-PK-18
J703-PK-18
START CONT
RELAY
094-2080
L975-PK-18
HEATER RELAY
9X-8124
607-PK-18
615-YL
12
L
GND
S
P
YL
BK
WH/BU
WH/YL
J703-PK-18
DIODE
121-1022
200-BK-18
330-YL-18
L975-PK-18
403-GN-18
308-YL-18
403-GN-18
309-GY-18
CHECK TERM.
RELAY
KEY SW.(START)
GND
KEY SW.(ON)
REGULATOR
L975-PK-18
TEMP.
115-PK-14
403-GN-18
XX
308-YL-18
101-RD-6
R
WH/GN
309-GY-18
309-GY-18
L908-OR
L909-BU
235-BK
E
D
C
B
A
877-YL-4
101-RD-4
235-BK
L909-BU
L908-OR
L909-BU
L908-OR
235-BK
308-YL-18
310-PU-18
200-BK-18
C
B
A
177-RD-14
513-OR-18
V
177-RD-14
T
NOTE F: USE FOR JAPAN.
615-YL-18
A584-BU-18
A583-YL-18
A587-YL-18
506-PU-18
615-YL-18
615-YL-18
615-YL
615-YL
A590-BU-18
A589-OR-18
191-WH-14
103-RD-18
118-GY
103-RD-18
129-BU-18
K905-RD-14
508-PU-18
509-WH-18
511-BR-18
512-GN-18
590-GY-18
501-GN-18
A586-OR-18
200-BK-14
200-BK-14
K997-BU-18
403-GN-18
200-BK-18
K905-RD-14
235-BK-14
K911-PK-18
K912-GN-18
CAB
DOME LAMP
096-0721
2
3
4
5
6
1
8
7
ATCH SPEAKER(L)
7Y-5505
ATCH SPEAKER(R)
7Y-5505
2
1
8
3
5
4
7
6
200-BK-18
200-BK-18
200-BK-18
ATCH
WINDOW LIMIT SW
117-6306(NOTE C)
ATCH
WINDOW CONT
117-6305
7
6
5
NOTE E: USE FOR OUTSIDE JAPAN.
4
3
8
1
2
5
4
3
2
1
6
E
E
E
E
E
E E D D
A A A A
R. LIMIT
GND
F. LIMIT
+B
WIPER
200-BK-18
200-BK-18
200-BK-18
A584-BU-18
615-YL
200-BK-18
A591-PU-18
A591-PU-18
200-BK-18
200-BK-14
200-BK
200-BK-18
615-YL-18
403-GN-18
129-BU-18
103-RD-18
K912-GN-18
K911-PK-18
K997-BU-18
200-BK-14
A586-OR-18
501-GN-18
590-GY-18
A583-YL-18
A584-BU-18
506-PU-18
118-GY
512-GN-18
511-BR-18
509-WH-18
508-PU-18
NEUTRAL
SW. DOWN
SW. UP
103-RD-18
200-BK-14
615-YL
A584-BU-18
191-WH-14
A583-YL-18
A587-YL-18
A589-OR-18
C537-GN-18
C538-OR-18
E
A590-BU-18
L972-BU-18
308-YL-18
A758-BR-18
A757-GY-18
A756-BU-18
A755-PK-18
K912-GN-18
K911-PK-18
235-BK-18
L909-BU-18
L908-OR-18
487-OR-18
954-GN-18
L972-BU-18
A758-BR-18
A757-GY-18
200-BK-18
L975-PK-18
K912-GN-18
K911-PK-18
A756-BU-18
A755-PK-18
235-BK-18
K905-RD-18
308-YL-18
235-BK-18
K905-RD-18
235-BK-14
K905-RD-14
F771-OR-18
F772-WH-18
K907-BU-18
L968-OR-18
L969-WH-18
L971-GN-18
L970-GY-18
A761-PU-18
200-BK-18
F771-OR-18
K904-GN-18
496-WH-18
430-BU-18
F772-WH-18
495-GN-18
K907-BU-18
L968-OR-18
491-PK-18
492-GY-18
MONITOR +B OUT
THROTTLE DIAL S1
THROTTLE DIAL S2
THROTTLE DIAL S3
THROTTLE DIAL S4
GOV ACTR (A)
EPR VALVE (+)
GOV ACTR (B)
GOV ACTR FDBK
COOLANT LEVEL SW
TRAVEL SPEED SOL
ENG SPEED SENSOR (-)
ENG SPEED SENSOR (+)
TRENCHING SOL
IMPLEMENT PRESS. SW
ENG OIL LEVEL SW
FUEL LEVEL SENSOR
405-GY-18
321-BR-18
FRONT PUMP PRESS. SENSOR
HYD OIL LEVEL SW
AIR CLEANER SW
L969-WH-18
HYD OIL TEMP SENDER
RS485 - (VALVE CONT)
RS485 + (VALVE CONT)
RS232C (GND)
RS232C (RX)
COOLANT SENSOR
9
20
10
28
31
26
13
30
29
35
40
2
6
39
6
24
25
22
15
ALTERNATOR (P TERM.)
RS485 - (RH JOYSTICK)
7
38
12
TRAVEL ALARM
ENG OIL PRESS. SW
36
SWING BRAKE SOL
C468-BU-18
412-BU-18
763-BU-18
A762-PU-18
788-YL-18
23
EPR VALVE (-)
17
21
8
RS485 + (LH JOYSTICK)
7
L977-YL-18
8
L974-GN-18
L978-GY-18
A771-PU-18
RS485 - (LH JOYSTICK)
RS485 + (PEDAL)
9
403-GN-18
10
RS485 + (SEMI AUTO)
RS485 - (PEDAL)
RS485 + (RADIO CONT)
17
HYD TANK PRESS. SW
RS485 + (MONITOR)
RS485 - (SEMI AUTO)
HYD TANK INDICATOR
RS485 + (RH JOYSTICK)
RS485 - (MONITOR)
27
18
TRAVEL PRESS. SW
HYD OIL FILTER INDICATOR
18
RS485 - (RADIO CONT)
RS485 + (ELEC GOV)
19
+B
+B
AIH INDICATOR
FINE SWING SW
K997-BU-18
BOOM RAISE PRESS. SW
LEVEL FINISH SOL
DUAL PWR SOL
AUX HYD PRESS. SW
32
33
25
KEY SW ON
RS485 - (ELEC GOV)
26
12
40
2
4
28
27
LOW IDLE SW
21
20
1
11
22
34
3
24
23
14
13
16
15
5
36
35
29
31
30
39
38
37
GND
GND
HAMMER PRESS. SW
RS232C (TX)
KEY SW START
A
37
4
3
OPTION SENSOR (PWM)
ATCH
ANTENNA
106-0036
1
16
19
5
OPTION SENSOR (PWM)
32
33
14
11
34
JOYSTICK +B OUT
A A
AA
A A
2
3
4
5
6
1
K905-RD-14
235-BK-14
L975-PK-18
954-GN-18
K997-BU-18
L970-GY-18
L971-GN-18
487-OR-18
A761-PU-18
K904-GN-18
496-WH-18
430-BU-18
K997-BU-18
495-GN-18
491-PK-18
492-GY-18
405-GY-18
7
8
1
6
5
4
3
2
321-BR-18
C468-BU-18
412-BU-18
2
3
4
5
6
11
1
10
9
8
7
12
763-BU-18
A762-PU-18
788-YL-18
403-GN-18
L977-YL-18
L974-GN-18
L978-GY-18
A771-PU-18
K997-BU-18
K997-BU-18
L908-OR-18
L909-BU-18
235-BK-18
A
L10
A
L970-GY-18
954-GN-18
BK
YL
177-RD-14
GN-18
BU-18
616-BU
322-GY-18
607-PK-18
168-RD-14
200-BK-18
200-BK-18
200-BK-18
200-BK-18
K906-GN-18
495-GN-18
SWING BRAKE
SOL
121-1491
B
2
1
200-BK-18
200-BK-18
K906-GN-18
PP
FUEL
SENSOR
105-9911
ATCH
REFUELING SW
5C-6108
2
1
B
325-PK-18
495-GN-18
616-BU
322-GY-18
607-PK-18
168-RD-14
200-BK
200-BK-14
168-RD-14
607-PK-18
200-BK-18
322-GY-18
200-BK-18
200-BK
616-BU
200-BK-18
607-PK-18
168-RD-14
A
B
NB
S S
200-BK-18
200-BK
607-PK-18
200-BK-18
616-BU
200-BK-18
200-BK-14
200-BK-18
322-GY-18
200-BK
200-BK-18
322-GY-18
N
NOTE N: USE WITH X272,X275.
200-BK
S
168-RD-18
200-BK-14
L976-GN-18
B
B
B
B
ATCH
BOOM LAMP
153-2521
CHASSIS
ATCH
REFUELING
PUMP
123-3928
ATCH
REFUELING
START SW(NO)
6T-9442
R
N
N
HORN
7Y-3919
J
K
J
K
200-BK-18
323-WH-14
+
-
616-BU
1
2
200-BK-14
ATCH
REFUELING
RELAY 2
149-5050
ATCH
REFUELING
RELAY 1
149-5050
200-BK-14
168-RD-14
168-RD-14
168-RD-18
168-RD-14
168-RD-14
200-BK-18
365-YL-18
L976-GN-18
325-PK-18
365-YL-18
RR
ATCH
REFUELING
STOP SW(NC)
9X-4184
365-YL-18
L976-GN-18
L976-GN-18
200-BK-18
365-YL-18
L976-GN-18
322-GY-18
616-BU
CHASSIS
LAMP
153-2523
ATCH
BOOM LAMP
153-2521
B PP
325-PK-18
325-PK-18 325-PK-18
1
2
2
1
1
2
325-PK-18
325-PK-18 325-PK-18
C
2
1
HORN
7Y-3920
L4
L3
L3
L4
L1
NN
EE
EE
2
1
GROUND STRAP
134-3344
147-PU-18
576-PK-18
575-YL-18
F773-OR-18
F774-WH-18
A770-PK-18
A769-GY-18
A768-BU-18
K906-GN-18
578-BU-18
307-OR-18
308-YL-18
791-PK-18
786-GN-18
152-BU
185-YL-18
105-RD-14
113-OR-18
615-YL-18
191-WH-18
530-OR-18
501-GN-18
A589-OR-18
A590-BU-18
L972-BU-18
A758-BR-18
A757-GY-18
A756-BU-18
A755-PK-18
K907-BU-18
L968-OR-18
L969-WH-18
147-PU-18
F772-WH-18
A537-PK-18
A537-PK-18
200-BK-18
2
1
A537-PK-18
147-PU-18
ATCH
SEAT WITH
SEAT HEATER
111-6458
200-BK-18
MM
615-YL-18
615-YL-18
A537-PK-18
147-PU-18
G
ATCH LOWER
WIPER SW
111-4785
ATCH LOWER
WASHER SW
111-4786
F771-OR-18
308-YL-18
G
ATCH POWER
WINDOW SW
111-4789
590-GY-18
A
147-PU-18
K909-BU-18
200-BK-18
200-BK-18
FF
FFFF
ATCH SEAT
HEATER SW
111-4783
2
1
147-PU-18
147-PU-18
116-BR-14
147-PU-18
147-PU-18
147-PU-18
147-PU-18
177-RD-14
177-RD-14
308-YL-18
200-BK-18
308-YL-18
116-BR-14
954-GN-18
L970-GY-18
2
1
2
1
2
4
1
L14
L10
3
L15
L13
C
B
A
L12
L9
L11
WW
GG
HH
SS(NOTE P)
AE(NOTE R)
UU(NOTE P)
AD(NOTE R)
ZZ(NOTE P)
AC(NOTE R)
VV
XX
VV
YY
UU(NOTE P)
AD(NOTE R)
1
2
2
1
1
2
WW
GG
ENG
GROUND STRAP
132-1805
1
2
1
1
2
2
116-BR-14
BB
(NOTE K)
(NOTE N)
103-RD-18
508-PU-18
200-BK-18
113-OR-18
103-RD-18
511-BR-18
6
4
2
5
1
3
ANTENNA
200-BK-18
509-WH-18
512-GN-18
8
7
1
2
3
4
5
6
2
G974-WH-18
G975-YL-18
Y
FAN RELAY
149-5050
HH
116-BR-14
116-BR-14
A588-GN-18
YY
ZZ(NOTE P)
AC(NOTE R)
L22
L23
L21
CC
10A
SEAT HEATER
147-PU-18
954-GN-18
L970-GY-18
PP
SS
UU
GG
HH
RELAY PANEL
147-PU-18
CRUSH SOL
L22
L23
L22
L23
L17
L16
L21
L10
L14
L14
L10
L20
L1
L25
L15
L25
L8
L19
L18
L11L12
L17
L13
L19
L5
L6
L6
L17
L15
L16
L12
L9
L13
147-PU-18
147-PU-18
L14
147-PU-18
147-PU-18
147-PU-18
B
308-YL-18
L8
L7
L7
L25
L3
L4
L4
L9
L15
L4
L3
L1
L3
YY
NOTE J: USE WITH A/C UNIT.
HH
P
D
NOTE G: USE WITH X270,X271,X297,X298.
NOTE H: USE WITH X272,X273,X275,X299,X300,X302.
STRAP AS.
DD
NOTE A: NORMALLY OPEN BEFORE REFRIGERANT CHARGE.
EE
H
W
163-6668
163-6667
163-6693
163-6692
163-6691
167-3579
150-6987
140-0851
140-0850
116-0258
150-7002
150-7003
128-8936
111-4826
132-1804
116-0080
4I-5422
111-4830
111-4841
116-0243
145-0560
121-1010
153-2542
150-7010
150-6989
153-2555
167-3494
121-1036
167-3496
111-4829
116-0096
116-0098
150-7009
150-7026
150-7022
153-2492
7G-1060
132-1827
128-8938
128-8937
116-0234
116-0233
111-4831
134-3344
132-1805
167-3495
HARNESS AS.
C-3
D-6
H-7
H-9
G-7
G-8
E-5
D-8
H-3
H-5
E-5
H-2
H-9
G-7
G-9
F-9
F-9
G-7
H-3
G-1
C-2
C-2
H-4
E-4
B-6
B-5
G-8
A-2
B-2
G-7
B-2
B-3
G-3
H-2
J-2
E-9
G-6
A-2
H-7
H-9
G-7
G-7
G-7
G-9
A-9
G-8
(NOTE T)
(NOTE T)
(NOTE R)
(NOTE R)
(NOTE R)
(NOTE R)
(NOTE N)
(NOTE K)
(NOTE K)
(NOTE N)
(NOTE N)
(NOTE P)
(NOTE P)
(NOTE E)
(NOTE P)
(NOTE P)
(NOTE K)
E97828
PART NUMBER: 121-0983 HE09
UNLESS OTHERWISE SPECIFIED ALL WIRE IS 16 GAUGE.
TO MACHINE STRUCTURE
L908-OR-18
L909-BU-18
403-GN-18
235-BK-18
L908-OR-18
L909-BU-18
235-BK-18
SERVICE
CONN 1
CONNECTOR
CONN 2
CONN 3 CONN 4
CONN 11
CONN 12
CONN 7
CONN 7
CONN 7
CONN 7
CONN 5
CONN 6
CONN 8
CONN 9
CONN 10
CONN 13CONN 14
CONN 15CONN 16
CONN 17
CONN 17
CONN 18
CONN 19 CONN 20
CONN 21
CONN 22
CONN 23
CONN 24 CONN 25
CONN 26
CONN 27
CONN 28
CONN 29 CONN 30
CONN 34
CONN 34
CONN 34
CONN 35
CONN 36
CONN 38
CONN 37
CONN 31 CONN 32
CONN 33
ALL DASHED LINES ARE ATTACHMENTS.
WIRES THAT HAVE BATTERY VOLTAGE
WHEN THE KEY SWITCH IS OFF.
WIRES THAT HAVE BATTERY VOLTAGE
WHEN THE KEY SWITCH IS ON.
STARTING CIRCUIT.
GAUGE CIRCUIT.
WIPER/WASHER CIRCUIT.
HEATER AND AIR CONDITIONER CIRCUIT.
GROUND CIRCUIT.
ENGINE/PUMP CONTROL CIRCUIT.
START AID CIRCUIT.