Component Location
Component
Schematic
Location
Machine
Location
Component
Schematic
Location
Machine
Location
Actuator - Governor A-12 1 Relay - Safety E-9 9D
Alarm - Action D-2 3A Relay - Starter B-12 21
Alarm - Travel D-11 2 Relay - Washer E-8 7D
Alternator B-12 3 Relay - Wiper E-8 7D
Antenna C-6 4 Resistor - Backup E-5 1C
Battery C-9 5 Sensor - Engine Coolant Temperature B-12 22
Block - Terminal D-9 1D Sensor - Fuel Level B-5 23
Breaker D-9 4D Sensor - Hydraulic Oil Temperature B-8 1F
Controller F-12 6 Sensor - Speed B-10 24
Converter B-7 7 Solenoid - Air Conditioner Compress Clutch C-12 25
Dial - Engine Speed C-2 3B Solenoid - Engine Shutdown B-10 26
Fuse - Block F-7, 8, 9 6D Solenoid - Level A-8 5F
Heater- Air B-10 8 Solenoid - Travel Speed A-8 3F
Horn A-2, B-2 9 Solenoid - Trenching A-8 2F
Lamp-Boom A-1,B-1 10 Speaker B-6 27
Lamp - Cab E-1, F-1 11 Switch - Boom Raise Press B-8 3E
Lamp - Chassis A-2 12 Switch - Disconnect D-9 5D
Lamp - Dome D-6 13 Switch - Engine Oil Press B-12 28
Lighter - Cigar E-3 1A Switch - Governor Backup C-5 4B
Meter - Service E-2 2A Switch - Horn F-3 30
Monitor E-2 4A Switch - Implement Swing Press C-8 1E
Motor - Lower Washer F-12 14 Switch - Low Idle D-3 2B
Motor - Lower Wiper F-2 15 Switch - Lower Washer B-3 6B
Motor - Starter A-12 16 Switch - Lower Wiper C-3 7B
Motor - Washer F-12 17 Switch - Neutral Start F-2 29
Motor - Wiper F-2 18 Switch - Pump Backup E-4 20
Pump - Refueling A-3 19 Switch - Refrigerant Low Press D-12 30
Radio C-6 20 Switch - Refueling A-5 31
Relay - Boom Lamp E-8 7D Switch - Refueling Pump A-3 32
Relay - Chassis/Cab Lamp E-8 7D Switch - Speed Change B-4 5B
Relay - Engine Shutdown D-7 2D Switch - Starter C-2 1B
Relay - Heater D-8 8D Switch - Travel Press C-8 2E
Relay - Horn E-7 7D Unit - Air Conditioner D-6 33
Relay - Main D-7 3D Unit - Heater E-6 34
Relay - Refueling Pump E-7 7D Valve - Proportional Reducing A-8 4F
A = Components in monitor panel.
B = Components in R.H. console.
C = Components in L.H. console.
D = Components in relay panel.
E = Components near control valve.
F = Components near manifold block.
Harness Connector Location
Connector
Machine
Location
Harness And/Or Components
Schematic
Location
Connector
Machine
Location
Harness And/Or Components
Schematic
Location
40 Contacts
CONN1
*
A - 4I5420
Controller
D-12
CONN12
C - 7Y8139
E - 5I8216
C-6
24 Contacts
CONN2
*
A - 4I5420
Controller
F-12
CONN30
A
D - 7Y3898
Monitor
E-2
CONN9
D
A - 4I5420
B - 4I5418
D-11
CONN32
F - 5I8217
Wiper Motor
F-2
CONN8
D
A - 4I5420
B - 4I5418
D-10
CONN12
S - 7Y8105
E - 5I8216
C-7
CONN13
A
A - 4I5420
E - 5I8216
C-5
CONN43
C - 7Y8139
Speaker
B-6
CONN24
A - 4I5420
G - 7Y3922
D-3
CONN21
B
H - 4I5463
Lower Wiper Switch
C-3
CONN18
B
A - 4I5420
H - 4I5463
D-4
CONN29
S - 7Y8105
Converter
B-7
CONN17
C
A - 4I5420
K - 7Y3923
E-5
CONN16
C
A - 4l5420
Backup Resistor
E-5
CONN3
D
A - 4I5420
L - 4I5458
E-9
CONN25
A - 4I5420
G - 7Y3922
D-3
CONN5
D
A - 4I5420
L - 4I5458
F-9
CONN23
A - 4I5420
J - 7Y3868
F-3
CONN6
D
A - 4I5420
L - 415458
F-9
CONN39
A - 4I5420
Refrigerant Switch
D-12
CONN4
D
B - 4I5418
L - 4I5458
E-9
CONN45
A - 4I5420
Travel Alarm
D-11
9 Contacts
CONN57
C - 7Y8139
Radio
C-6
CONN50
E
B - 4I5418
Boom Raise Press Switch
B-8
7 Contacts
CONN14
A
A - 4I5420
D - 7Y3898
C-5
CONN49
B - 4I5418
Fuel Level Sensor
B-5
CONN10
D
A - 4I5420
B - 4I5418
D-10
CONN51
E
B - 4I5418
Implement Swing Press Switch
C-8
CONN11
D
B - 4l5418
Safety Relay
E-9
CONN53
F
B - 4I5418
Level Solenoid
A-8
CONN28
E - 5I8216
F - 5I8217
E-2
CONN38
B - 4I5418
N - 4I5460
B-2
CONN15
A - 4I5420
Air Conditioner Unit
D-6
CONN48
B - 4I5418
PP - 5I8258
A-6
CONN19
B
A - 4I5420
H - 4I5463
D-4
CONN56
F
B - 4I5418
Proportional Reducing Valve
A-8
CONN15
A - 4I5420
Heater Unit
E-6
CONN41
B - 4I5418
Refueling_Pump
A-3
CONN44
B - 4I5418
Governor Actuator
A-11
CONN34
B - 4I5418
Refueling Pump Switch
A-3
CONN27
B
G - 7Y3922
Engine Speed Dial
C-2
CONN42
B - 4I5418
Speed Sensor
B-10
CONN58
A - 4I5420
A - 4I5420
D-12
CONN52
E
B - 4I5418
Travel Press Switch
C-8
CONN33
A - 4I5420
Lower Wiper Motor
F-2
CONN55
F
B - 4I5418
Travel Speed Solenoid
A-8
CONN54
F
B - 4I5418
Trenching Solenoid
A-8
CONN20
C
J - 7Y3868
R - 096-1615
F-3
CONN31
A
D - 7Y3898
Action Alarm
D-2
CONN7
S - 7Y8105
Converter
B-7
CONN35
E - 5I8216
M - 7Y8245
F-1
CONN37
B - 4I5418
Air Conditioner Clutch Solenoid
C-12
CONN26
B
G - 7Y3922
R - 096-1615
D-3
CONN36
E - 5I8216
M - 7Y8245
E-1
CONN22
B
H - 415463
Lower Washer Switch
B-3
A = Connector in lower cab.
B = Connector in operators R.H. console.
C = Connector in operators L.H. console.
D = Connector in relay box.
E = Connector near control valve.
F = Connector near pilot manifold.
* = Connector in controller compartment
4 Contacts
3 Contacts
2 Contacts
2 Contacts
2 Contacts
10 Contacts
6 Contacts
5 Contacts
4 Contacts
1
2
5
2
3
7
4
3
4
2
4
5
3
6
7
1
2
22
4
6
3
2
16
1
15
14
13
12
2
11
8
9
1
8
5
10
17
18
4
19
20
21
3
2
3
23
24
25
3
1
1
1
4
8
6
A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
3
4
5
6
8
9
11
11
12
14
15
16
B
C
D
E
1
2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
7
F
17
18
19
20
22
21
23
24
25
29
Machine Harness Connector And Component Locations
A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
3
4
5
8
9
10
11
12
14
15
16
B
C
D
E
1
2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
7
F
17
18
19
20
21
22
23
24
25
13
9
10
10
1
2
3
4
3
4
5
6
1
2
4
3
1
2
5
6
3
4
1
2
F
D
E
D
1
2
3
4
1
2
7
G
3
4
H
A
A
AREA A
AREA B
1
2
3
4
5
6
7
8
3
4
5
6
8
9
1
2
7
1
2
3
3
1
2
A
A
K
AREA C
KK
A
AREA D
B
HH
1
2
3
3
1
2
1
2
4
3
3
4
5
1
2
AREA F
AREA E
B
B
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.
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
SENR6129
June 1993
311 & 312 Excavators
Electrical System
311:
9LJ1-UP
312:
6GK1-392
©
1993 Caterpillar
All Rights Reserved
Printed in U.S.A.
B751-YL
513-OR
306-GN
A
B
C
123
D
E
F
123
4
5
6
4
56
78
9
789
101112
A
B
C
101112
D
E
F
1
2
1
2
3
PREHT
BR
OFF
ON
START
ACC
R1
R2
C
B
+ -
S
MOTOR
T
1
2
1
2
POS
NEG
POS
NEG
6
7
8
9
5
4
3
2
1
10
1
2
1
2
ALT
T
1
21
2
6
8
9
5
4
3
2
1
10
6
5
4
3
2
1
MOTOR MOTOR
6
7
8
9
5
4
3
2
1
10
HARNESS AS.
LOCPART NO.IDENT
CIRCUIT GROUPING
DESIGNATION
#L
ATCH WIRE, CABLE,
COMPONENT
CIRCUIT NOT CONNECTED
CIRCUIT CONNECTED
BLUE
GREEN
BU
GN
RD
WH
OR
YL
PK
BK
BLADE, SPADE, RING,
OR SCREW TERMINAL
INTERNAL ELECTRICAL
CONNECTION TO SURFACE
OF COMPONENT
ELECTRICAL CONNECTION
TO VEHICLE STRUCTURE
CONNECTOR
SYMBOL DESCRIPTION
BROWN
PURPLE
GRAY
BLACK
COLORABBREV
PINK
YELLOW
ORANGE
WHITE
RED
BR
PU
GY
A 4I-5403 D-10 D
B 105-9920 D-10
C 7Y-8139 C-6
D 5I-8217 E-2
E 4I-5407 C-5
F 5I-8216 C-6
G 7Y-3922 D-3
H 4I-5463 D-4
J 7Y-3868 F-3
K 4I-5411 E-5
L 4I-5458 F-9
M 7Y-8245 F-1
N 4I-5460 B-2
P 7Y-3994 B-2
WIRE AS.
JJ 7Y-3937 D-7
KK 4I-5448 D-9
LL 4I-5447 D-9
MM 4I-5451 D-9
PP 5I-8358 A-5
CABLE AS.
AA 4I-5422 C-9
BB 7Y-3946 C-9
CC 4I-5428 C-9
DD 7Y-3947 D-9
EE 4I-5429 A-9
FF 7Y-3936 D-9
GG 7Y-3935 D-9
THIS SCHEMATIC IS FOR THE 311, 312 EXCAVATORS.
COMPONENTS ARE SHOWN INSTALLED ON AFULLY
OPERABLE MACHINE WITH THE KEY AND ENGINE OFF.
(4I-5402).
NOTE A :
NOTE B :
NORMALLY OPEN BEFORE REFRIGERANT CHARGE.
USE WITH COLD WEATHER.
COM
S1
S2
S3
S4
1
2
3
4
5
ENG SPEED
DIAL
7Y-5465
KEY SW
7Y-3918
ATCH LOWER
WIPER SW
7X-6388
ATCH LOWER
WASHER SW
7X-6387
1
2
200-BK
A755-PK
A756-BU
A757-GY
A758-BR
309-GY
308-YL
310-PU
310-PU
307-OR
105-BR
576-PK
152-BU
575-YL
152-BU
578-BU
616-BU
322-GY
200-BK
235-BK
200-BK
616-BU
616-BU
200-BK
200-BK
616-BU
200-BK
607-PK
200-BK
322-GY
200-BK
322-GY
322-GY
200-BK
200-BK
200-BK
235-BK
200-BK
200-BK
200-BK
CHASSIS
200-BK
616-BU
HORN
7Y-3919
HORN
7Y-3920
ATCH
BOOM
LAMP
5I-8250
ATCH
BOOM
LAMP
5I-8250
CHASSIS
LAMP
5I-8251
1
2
1
2
3
4
MOTOR
+1
-+
576-PK
152-BU
575-YL
200-BK
501-GN
500-BR
200-BK
ATCH
CAB LAMP
5I-8250
2
1
ATCH
CAB LAMP
5I-8250
200-BK
500-BR
501-GN
200-BK
501-GN
500-BR
200-BK
200-BK
575-YL
152-BU
576-PK
1
2
3
4
1
2
1
2
6
7
8
9
5
4
3
2
1
10
1
2
+
-
DATA +
DATA -
+BATTERY
GROUND
B955-YL
B956-PK
113-OR
201-BK
403-GN
200-BK
113-OR
410-WH
200-BK
307-OR
A755-PK
A756-BU
A757-GY
A758-BR
309-GY
105-BR
310-PU
308-YL
B786-BU
200-BK
200-BK
B786-BU
307-OR
306-GN
200-BK
320-OR
576-PK
152-BU
575-YL
200-BK
306-GN
307-OR
HORN SW
6I-5088
NEUTRAL
START SW
9W-2150
306-GN
575-YL
152-BU
576-PK
320-OR
200-BK
200-BK
129-BU
129-BU
B955-YL
B956-PK
403-GN
200-BK
113-OR
410-WH
MONITOR
7Y-5500
SERVICE
METER
6T-7337
ACTION
ALARM
3E-6328
CIGAR
LIGHTER
9W-0335
CAB
ONE TOUCH
LOW IDLE SW
6I-5088
B790-OR
B789-BR
B790-OR
B790-OR
185-YL
200-BK
A763-GY
B751-YL
B740-OR
B790-OR
B790-OR
B739-WH
B789-BR
B789-BR
B751-YL
185-YL
200-BK
B740-OR
B790-OR
B739-WH
B789-BR
576-PK
152-BU
575-YL
152-BU
578-BU
GOV
BACKUP SW
3T-4405
SPEED
CHANGE SW
7N-8008
6
7
8
9
5
4
3
2
1
10
200-BK
120-YL
103-YL
615-YL
500-BR
501-GN
118-GY
113-OR
129-BU
403-GN
410-WH
B955-YL
B956-PK
200-BK
200-BK
200-BK
615-YL
500-BR
501-GN
118-GY
200-BK
200-BK
200-BK
200-BK
200-BK
CAB
1
2
1
2
1
2
323-WH
200-BK
365-YL
325-PK
325-PK325-PK
325-PK
365-YL
323-WH
607-PK
322-GY
616-BU
200-BK
235-BK
235-BK
GY
GN
+
-
ATCH
REFUELING
PUMP
6C-5572
ATCH
REFUELING
PUMP SW AS.
105-9894
FUEL
SENSOR
7Y-3848
ATCH
REFUELING SW
5C-6108
6
7
8
9
5
4
3
2
1
10
200-BK
185-YL
B730-OR
B731-WH
A768-BU
A768-BU
A769-GY
B731-WH
185-YL
B730-OR
A770-PK
BACKUP
RESISTOR
102-8015
PUMP
BACKUP SW
3T-4405
200-BK-14
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK
6
7
8
9
5
4
3
2
1
10
576-PK
575-YL
152-BU
152-BU
578-BU
B751-YL
B790-OR
B739-WH
B789-BR
185-YL
B740-OR
200-BK
1
2
3
4
5
103-YL
200-BK
1
2
3
4
5
124-GN-14
519-PK
615-YL
103-YL
200-BK-14
306-GN
320-OR
A755-PK
A756-BU
A757-GY
A758-BR
105-BR
310-PU
308-YL
309-GY
B786-BU
578-BU
B790-OR
B740-OR
B789-BR
B739-WH
B751-YL
A763-GY
152-BU
185-YL
185-YL
A768-BU
A769-GY
B730-OR
B731-WH
B955-YL
410-WH
403-GN
129-BU
113-OR
118-GY
501-GN
500-BR
120-YL
103-YL
615-YL
615-YL
103-YL
519-PK
124-GN-14
200-BK
307-OR
B956-PK
CHASSIS PLATFORM
PLATFORM
PLATFORM
DOME
LAMP
096-0721
B737-GN
200-BK
200-BK 2
1
1
2200-BK
A771-PU
D764-GN
TRAVEL SW
102-8041
IMPLEMENT SW
102-8041
BOOM
RAISE SW
102-8042
B737-GN
A771-PU
200-BK
D764-GN
2
1
1
2
2
1
200-BK
491-PK
142-BU
B964-YL
142-BU
142-BU
B965-GY
A768-BU
A769-GY
HYD OIL
SENDER
4I-5394
LEVEL
FINISH
4I-5674
TRENCHING
4I-5674
TRAVEL
SPEED
4I-5674
PROPORTIONAL
REDUCING
VALVE
A769-GY
A768-BU
B965-GY
B964-YL
491-PK
200-BK
B737-GN
D764-GN
200-BK
A771-PU
200-BK
491-PK
B964-YL
B965-GY
A768-BU
A769-GY
616-BU
322-GY
607-PK
323-WH
365-YL
200-BK
BK-00BK-00
BK-00
10A
10A
10A
10A
10A
10A 10A
10A
10A
15A
10A
10A 10A
10A
15A
10A
20A
10A
CAB/CHASSIS LAMP
BOOM LAMP
RADIO
MONITOR
SOLENOID
HORN
DOME LAMP
ENG/PUMP CONT
TRAVEL ALARM
WASHER/WIPER
LOWER WASHER/WIPER
KEY SW
REFUELING
BACKUP
CIGAR LIGHTER
A/C HEATER
105-BR
185-YL-14
129-BU
124-GN-14
WIPER
RELAY
7Y-5490
WASHER
RELAY
7Y-5490
HORN
RELAY
7Y-5490
CAB/CHASSIS
LAMP RELAY
7Y-5490
BOOM
LAMP
RELAY
7Y-5490
ATCH
REFUELING
RELAY
7Y-5490
118-GY
500-BR
792-OR
118-GY
501-GN
501-GN
501-GN
118-GY
118-GY
A983-BU
506-PU
320-OR
322-GY114-GN
115-PK 615-YL
607-PK
786-GN
616-BU149-PU 168-GN
365-YL
323-WH
10
1
2
3
4
5
9
8
7
6
6
7
8
9
5
4
3
2
1
10
308-YL
310-PU
105-BR
185-YL-14
129-BU
124-GN-14
320-OR
500-BR
501-GN
103-YL
118-GY
152-BU
120-YL
615-YL
113-OR
184-BU
786-GN
332-BU
506-PU
121-YL
792-OR
791-PK
A983-BU
877-YL
10
1
2
3
4
5
9
8
7
6
616-BU
607-PK
323-WH
365-YL
322-GY
142-BU-14
109-OR-6
109-OR-6
101-RD-6
101-RD-4
877-YL-4
327-PK-10
101-RD-14
101-RD-14
101-RD-6
60A
ALT
BREAKER
9S-0174
WH/GN
YL
WH/BU
BK
WH/YL
403-GN
403-GN
309-GY
309-GY
330-YL
200-BK
D746-PK
D746-PK
L
R
S
P
GROUND
308-YL
112-PU-14
112-PU-14
112-PU-14
112-PU-14
112-PU-14
200-BK
109-OR-6
109-OR-10
327-PK-10
877-YL-4
877-YL
310-PU
101-RD-4
109-OR-10
HEATER
RELAY
085-5353
ENG
SHUTDOWN
RELAY
9X-8124
MAIN
RELAY
3T-0376
BK-00
BK-00
200-BK
200-BK
332-BU
112-PU-14
112-PU-14
112-PU-14
112-PU-14
112-PU-14
322-GY
365-YL
323-WH
607-PK
616-BU
877-YL
A983-BU
791-PK
792-OR
121-YL
506-PU
332-BU
786-GN
184-BU
120-YL
113-OR
500-BR
118-GY
501-GN
615-YL
142-BU-14
115-PK
113-OR
120-YL
149-PU
615-YL
501-GN
118-GY
500-BR
113-OR
120-YL
114-GN
103-YL
184-BU
121-YL
118-GY
152-BU
103-YL
152-BU
320-OR
308-YL
310-PU
112-PU-14
112-PU-14
112-PU-14
101-RD-14
RELAY
PANEL
DISCONNECT SW
7N-0718
BLOCK
7Y-5499
5V+
GND
SIG
M
24V+
OR
GND
SIG
1
2
3
4
5
BK
PU
BU
YL
G
S
MOT
BAT
MOTOR
365-YL
323-WH
607-PK
322-GY
616-BU
A769-GY
A768-BU
B965-GY
B964-YL
491-PK
A771-PU
200-BK
D764-GN
B737-GN
877-YL-4
877-YL-4
A762-PU
788-YL
327-PK-10
327-PK-10
200-BK-10
200-BK-10
200-BK
200-BK
200-BK
200-BK-6
113-OR
200-BK
A761-PU
A763-GY
B751-YL
ENG
CHASSIS
AIR
HEATER
5I-7746
ENG
PICKUP
5I-7579
ENG
SHUTDOWN
SOL
5I-7518
513-OR
200-BK
200-BK
D746-PK
109-OR-6
403-GN
309-GY
200-BK-6
200-BK
200-BK
492-GY
405-GY
306-GN
330-YL
101-RD-4
RD-00
RD-00
B751-YL
A763-GY
A761-PU
200-BK
113-OR
200-BK-6
200-BK
200-BK
200-BK
327-PK-10
788-YL
A762-PU
877-YL-4
ALTERNATOR
5I-7982
COOLANT
TEMP
SENDER
5I-7578
ENG
OIL
SW
5I-7580
START
RELAY
STARTER
5I-7716
ENG GOV
ACTR
4I-5496
513-OR
D746-PK
109-OR-6
403-GN
309-GY
200-BK-6
492-GY
405-GY
306-GN
330-YL
101-RD-4
101-RD-4
330-YL
306-GN
405-GY
492-GY
200-BK-6
309-GY
403-GN
109-OR-6
D746-PK
513-OR
RD-00
RD-00
20
11
12
13
14
15
19
18
17
16
21
22
23
24
28
23
25
19
35
24
14
20
7
6
9
8
16
15
31
21
34
33
12
22
32
10
18
17
26
11
1
2
3
4
235-BK
264-BK
265-BK
266-BK
267-BK 267-BK
264-BK
GND
GND
HARNESS CODE 1
HARNESS CODE 2
HARNESS CODE 3
HARNESS CODE 4
RS232C TxD
RS232C RxD
OPTION RELAY 1
OPTION RELAY 2
OPTION RELAY 3
PWM OUT +
PWM OUT -
BOOM LAMP RELAY
308-YL
410-WH
A758-BR
A757-GY
A756-BU
A755-PK
B786-BU
B956-PK
B955-YL
B789-BR
B790-OR
B739-WH
B740-OR
B730-OR
B731-WH
A768-BU
877-YL
184-BU
A983-BU
792-OR
791-PKCHASSIS LAMP RELAY
WIPER MOTOR RELAY
WASHER RELAY
+B (24V)
GLOW
BACKUP SW 3
EPR VALVE +
EPR VALVE -
GOV ACTR +
GOV ACTR -
BACKUP SW 1
BACKUP SW 2
RS485 +
RS485 -
LOW IDLE SW
THROTTLE DIAL S1
THROTTLE DIAL S2
THROTTLE DIAL S3
THROTTLE DIAL S4
MONITOR ALARM
KEY SW
786-GN
491-PK
A771-PU
B737-GN
B965-GY
B964-YL
763-BU
495-GN
A761-PU
492-GY
405-GY
788-YL
A762-PU
D746-PK
D764-GN
321-BR
332-BU
HYD OIL TEMP SENSOR
IMPLEMENT SW
TRAVEL SW
TRENCHING SOLENOID
LEVEL FINISH SOLENOID
TRAVEL SOLENOID
FUEL LEVEL SENSOR
GOV ACTR SENSOR
COOLANT SENSOR
ENG OIL PRESS. SW
ENG PICKUP SENSOR +
ENG PICKUP SENSOR -
ALTERNATOR (P TERM.)
BOOM RAISE SW
TRAVEL ALARM
ENG SHUTDOWN RELAY
ATTACHMENT
OPTION SOLENOID
COOLANT LEVEL SW
ENG OIL LEVEL SW
HYD OIL LEVEL SW
OPTION SENSOR
OPTION SW 1
OPTION SW 2
ENG/PUMP
CONT
4I-5383
13
27
29
39
38
30
40
36
37
1
3
4
5
2
506-PU
200-BK
200-BK
578-BU
ATCH
LOWER
WASHER
7T-8890
WASHER
7T-8890
10
1
2
3
4
5
9
8
7
6
578-BU
200-BK
200-BK
506-PU
332-BU
321-BR
D764-GN
D746-PK
A762-PU
788-YL
405-GY
492-GY
A761-PU
495-GN
763-BU
B964-YL
B965-GY
B737-GN
A771-PU
491-PK
791-PK
792-OR
A983-BU
184-BU
877-YL
A768-BU
B731-WH
B730-OR
B740-OR
B739-WH
B790-OR
B789-BR
B955-YL
B956-PK
B786-BU
A755-PK
A756-BU
A757-GY
A758-BR
410-WH
308-YL
786-GN
266-BK
267-BK
235-BK
513-OR
519-PK
121-YL
321-BR
519-PK
513-OR
321-BR
121-YL
ATCH
REFRIGERANT SW
(NOTE A)
5I-3959
ATCH
TRAVEL
ALARM
3T-1444
121-YL
321-BR
513-OR
519-PK
513-OR
519-PK
578-BU
308-YL
410-WH
A758-BR
A757-GY
A756-BU
A755-PK
B786-BU
B956-PK
B955-YL
B789-BR
B790-OR
B739-WH
B740-OR
B730-OR
B731-WH
A768-BU
877-YL
184-BU
A983-BU
792-OR
791-PK
121-YL
786-GN
332-BU
506-PU
491-PK
A771-PU
B737-GN
B965-GY
B964-YL
763-BU
495-GN
A761-PU
492-GY
405-GY
788-YL
A762-PU
D746-PK
D764-GN
200-BK
200-BK
267-BK
266-BK
235-BK
235-BK
A768-BU
B731-WH
B730-OR
B740-OR
B739-WH
B790-OR
B789-BR
B955-YL
B956-PK
B786-BU
A755-PK
A756-BU
A757-GY
A758-BR
410-WH
308-YL
578-BU
519-PK
513-OR
113-OR
615-YL
152-BU
118-GY
103-YL
501-GN
500-BR
320-OR
124-GN-14
129-BU
185-YL-14
120-YL
105-BR
310-PU
308-YL
113-OR
A763-GY
A768-BU
A769-GY
309-GY
403-GN
405-GY
491-PK
492-GY
495-GN
763-BU
788-YL
A761-PU
A762-PU
D746-PK
A771-PU
B737-GN
B964-YL
B965-GY
D764-GN
403-GN
309-GY
D746-PK
403-GN
309-GY
D746-PK
330-YL
200-BK
142-BU-14
607-PK
877-YL-4
322-GY
616-BU
109-OR-6
101-RD-4
327-PK-10
365-YL
323-WH
403-GN
309-GY
A769-GY
A768-BU
A763-GY
306-GN
513-OR
B751-YL
113-OR
235-BK
235-BK
266-BK
267-BK
200-BK
200-BK BK-00
CHASSIS
A A A A
A
A
A
A
A A
A
B
B
A
A
B
DD
L12
L12
L13
L14
L17
L17 L17
L16
L16
L15
CONN 37
P
B
L
R
E
B
B
B
B B
B B
B
B
B
AA
B
EE
EE
B
B
CONN 42
B
L21
L21
L18
A L
A
L
L
A
B
B L
B
B
B
B
KK
KK
LL
GG
FF
MM
L
LL
KK
L13
L14
L15
L16
L12
L19
L20
L19
L
L
L
KK
JJ
L20
JJ
L
MM
GG
L
L
FF
L
CC
DD
SAFETY
RELAY
094-2080
FUSE
10A 9W-1442
15A 9W-1441
20A 9W-1446
BATTERY
3T-5760
9X-3404(NOTE B)
CCBBAA
L21
L22
L22
B
B
B
B
B
B
B
BB
OPERATOR STATION
L12
L12
L4
L5
L6
L7
L8
L6
L6
L9
L9
L5
L4
L5
L4
K
A
KK
A
A
H
A
H
L10
F
RELAY PANEL
RELAY PANEL
RELAY PANEL
L10
L8
L1
L2
L11
L22
L1
L2
H H H H
A A
F
E
OPERATOR STATION
1
2
3
4
5
7
6
B
B PP
PP
B
ATCH
LOWER
WIPER
4I-5019
WIPER
4I-6838
L4
L9
L5
L3
L2
L5
G
G
A A
G G
E
E
E E
E
D
F
F M
M
M
MFA D
S +1
A A
J
A
J
J
OPERATOR STATION
OPERATOR STATION
L1
L3
L1
L2
L11
L3
G
H
H
B N
N
P
P
B
B
B
200-BK
200-BK
2
1
B
325-PK
365-YL
365-YL
325-PK
200-BK
323-WH
200-BK
607-PK
200-BK
200-BK
235-BK
200-BK
322-GY
616-BU
607-PK
200-BK
323-WH
200-BK
325-PK
365-YL
118-GY118-GY118-GY
B789-BR
B789-BR
A763-GY
2
5
3
1
6
44
6
1
3
5
2
495-GN
L7
L6
L7
A769-GY
A763-GY
495-GN
168-GN
101-RD-14
BK-00
495-GN
235-BK
235-BK
L18
7
6
4
3
1
5
2
A
ATCH
A/C UNIT
4I-0470
200-BK-14
103-YL
615-YL
519-PK
124-GN-14
5
4
3
2
1
BK-18
RD-18
WH/RD-18
WH/BK-18
3
2
1
GROUND
+ BATTERY
+12 VOLT
GROUND
3
1
4
2
RADIO (NOTE D)
ATCH
ANTENNA
7Y-3990
TO RADIO
ATCH CONVERTER
7T-8000
120-YL
200-BK
135-BU
210-BK
R
R
R
R
HEATER UNIT
4I-1275
R 7Y-8105 C-7
NOTE C : USE WITH MODEL 312.
NOTE D : USE WITH MODEL 311.
ATCH A/C
CLUTCH
SOL
7T-8600
763-BU
763-BU
763-BU
763-BU
RD
BK
A
142-BU-14
142-BU-14
142-BU-14
GROUND STRAP
7G-1060
200-BK
615-YL
615-YL
200-BK
200-BK
200-BK
615-YL
615-YL
615-YL
109-OR
109-OR
NOTES
CONN 41
CONN 34
CONN 38
CONN 27
CONN 21
CONN 22
CONN 19
CONN 18
CONN 24
CONN 25
CONN 26
CONN 31
CONN 20
CONN 23
CONN 33
CONN 32
CONN 28
CONN 36
CONN 35
CONN 48
CONN 49
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.
ENGINE/PUMP CONTROLLER CIRCUIT.
WIPER/WASHER CIRCUIT.
HEATER AND AIR CONDITIONER CIRCUIT.
GROUND CIRCUIT.
ENGINE SHUTDOWN CIRCUIT.
AIR INLET HEATER CIRCUIT.
ALL DASHED LINES ARE ATTACHMENTS.
CONN 55
CONN 54
CONN 53
CONN 56
CONN 51
CONN 52
CONN 50
CONN 7
1
2
CONN 29
CONN 13
CONN 14
CONN 15
CONN 15
1
2
A770-PK
A770-PK
200-BK-4
CONN 16
CONN 17
TERMINAL
B
B
CONN 1
CONN 58
CONN 2
CONN 8
CONN 9
CONN 10
CONN 5
CONN 6
CONN 3
CONN 11
CONN 44
CONN 39 CONN 45
CONN 4
CONN 12
CONN 30
5I-8368
UNLESS OTHERWISE SPECIFIED ALL WIRE IS 16 GAGE.
A 4I-5405 D-10 C
