621E & 623 E WHEEL TRACTOR-SCRAPERS ELECTRICAL SCHEMATIC

©
1994 Caterpillar
All Rights Reserved
Printed in U.S.A.
SENR8631
August 1994
621E & 623E Wheel Tractor-Scrapers
Electrical System
6AB1428-UP
6YF197-UP
WIRE DESCRIPTION CHART
Wire Wire Wire Wire
Number Color Description
Number Color Description
Power Distribution Circuits Accessory Circuits
101 RD BAT 500 BR WIPER - FRONT (PARK)
102 BU HD LMP 501 GN WIPER - FRONT (LO)
103 YL AUX CKT 502 OR WIPER - FRONT (HI)
105 BR KEY SW 503 BR WIPER - REAR (PARK)
109 OR ALT OUTPUT (+) TERM. 504 YL WIPER - REAR (LO)
112 PU MAIN POWER RELAY OUTPUT 505 BU WIPER - REAR (HI)
113 OR OPRMON PANEL 506 PU WASHER - FRONT
114 GN WARNING HORN (FORWARD) 507 WH WASHER - REAR
117 YL AUX CKT 513 OR A/C COMPRESSOR/REFRIGERANT PRESS. SW
118 GY AUX CKT 515 GY BLOWER MOTOR (HI)
119 PK AUX CKT 516 GN BLOWER MOTOR (MEDIUM)
121 YL BACKUP ALARM TO LAMP 517 BU BLOWER MOTOR (LO)
122 BU AUX CKT 521 YL A/C SW TO REFRIGERANT SW
123 WH AUX CKT 522 WH A/C CLUTCH TO THERMOSTAT SW
124 GN A/C
Lighting Circuits
125 OR AUX CKT 600 BR DASH LAMP BASIC
126 PK XMSN CONT 601 GY DASH LAMP HI
165 YL AUX CKT 602 WH DOME LAMP
Ground Circuits
604 OR STOP LAMP
200 BK MAIN CHASSIS 608 GN FLOOD LAMP - REAR
201 BK OPR MON PANEL 609 YL FLOOD LAMP - SIDE
202 BK XMSN CONT 610 OR HEAD LAMP BASIC
203 BK CHASSIS DIAGNOSTIC 611 PU HEAD LAMP HI
204 BK OPR MON PANEL (SCRAPER) 614 PU PARK/TAIL/DASH LAMP
207 BK STARTER DIAGNOSTIC 619 GN HEAD LAMP LO
211 BK DISC DIAGNOSTIC RESISTOR 639 WH LEFT HAND STOP/TAIL LAMP
231 BK XMSN SW 640 GN RIGHT HAND STOP/TAIL LAMP
Basic Machine Circuits Control Circuits
301 BU STARTER NO.1 SOL 703 BU XMSN UP SOL
302 OR STARTER NO.1 RESISTOR TO DIAGNOSTIC 704 GY XMSN DOWN SOL
304 WH STARTER RELAY NO.1 OUTPUT 708 YL XMSN HOLD SW
306 GN STARTER RELAY COIL TO NEUT START SW 709 OR SENSOR POWER SUPPLY
OR KEY SW 710 GN XMSN SPEED PICKUP SIGNAL
307 OR KEY SW TO NEUT START SW 711 BR XMSN LEVER CODE 1
308 YL MAIN POWER RELAY COIL 712 WH XMSN LEVER CODE 2
310 PU START AID SW TO START AID SOL 713 OR XMSN LEVER CODE 3
311 WH START AID SOL TO TEMP SW 714 YL XMSN LEVER CODE 4
321 BR BCKP ALARM LAMP TRAVEL ALARM 715 GN XMSN LEVER CODE 5
322 GY WARNING HORN (FORWARD) 716 BU XMSN LEVER CODE 6
323 WH FUEL PUMP POWER 717 BR BOWL APRON SOL FLOAT/VCTC SOL
324 BU DIFF LOCK SOL 721 BR XMSN GEAR CODE 1
Monitoring Circuits
722 WH XMSN GEAR CODE 2
400 GN SERVICE METER SW 723 OR XMSN GEAR CODE 3
403 GN ALTERNATOR (R) TERM. 724 YL XMSN GEAR CODE 4
405 GY OPR MON OIL PRESS. (LO SETTING) 725 GN XMSN GEAR CODE 5
406 PU OPR MON COOLANT TEMP 726 BU XMSN GEAR CODE 6
407 PK OPR MON CONVERTER/RETARDER OIL TEMP 733 BR SWITCHING GEAR CODE 1 FRONT
408 WH OPR MON SYSTEM AIR PRESS. 734 WH SWITCHING GEAR CODE 2 FRONT
409 OR OPR MON NEUT 735 OR SWITCHING GEAR CODE 3 FRONT
410 WH OPR MON ACTION ALARM 736 YL SWITCHING GEAR CODE 4 FRONT
411 PK OPR MON ACTION LAMP 737 GN SWITCHING GEAR CODE 5 FRONT
412 BU OPR MON COOLANT FLOW 738 BR SWITCHING GEAR CODE 1 REAR
413 BR OPR MON FUEL PRESS. 739 WH SWITCHING GEAR CODE 2 REAR
415 GN OPR MON TEST SW 740 OR SWITCHING GEAR CODE 3 REAR
417 GY PRIMARY STER SW 741 YL SWITCHING GEAR CODE 4 REAR
419 YL OPR MON PARKING BRAKE 742 GN SWITCHING GEAR CODE 5 REAR
421 BU OPR MON ACTION LAMP (SCRAPER) 743 PU SWITCHING NEUT/RUN SW
422 YL OPR MON ACTION ALARM (SCRAPER) 744 BU SWITCHING UP SOL
423 PU OPR MON TEST SW (SCRAPER) 745 GY SWITCHING DOWN SOL
441 OR ENG COOLANT TEMP GAGE 746 PK SWITCHING SYNCHRONIZE SOL
444 BU CONVERTER/RETARDER OIL TEMP GAGE 747 WH SWITCHING NO SYNCHRONIZE SOL
445 GN CONVERTER/RETARDER OIL TEMP GAGE 781 PK AUGER BUFFER BOX TO NEUT START CONT
(SCRAPER) 787 WH AUGER BUFFER BOX
450 YL TACH SENDER (+) 895 BR AUGER BUFFER BOX TO NEUT START CONT
451 BR TACH SENDER (-) 896 GN AUGER BUFFER BOX TO AEM RESISTOR
470 PU CANE SW NEUT
A417 WH OPR MON SCRAPER XMSN
HARNESS CONNECTOR LOCATION CHART
Connectors
Machine
Location
Harness And/Or
Components
Schematic
Location
Connectors
Machine
Location
Harness And/or
Components
Schematic
Location
D - 8X-2348
F-7
P - 5T-1563 (82tE)
C-7
37 Contacts
Trans Control 6 Contacts A - 5T -1639 (82tE)
D - 8X-2348
C-4
P-2T-1878(623E)
C-7
W - 8X-2296 A - 2T-1910 (623E)
25 Contacts
A - 8W-7413
C-2
D - 8X-2348
C-3
W - 8X-2296 W - 8X-2296
W - 8X-2296
E-5
G - 5T-1632
F-4
20 Contacts
Diagnostic Conn W - 8X-2296
W - 8X-2296
E-3
W - 8X-2296
D-1
Operator Monitor 4 Contacts Y - 6G-9985
14 Contacts
D - 8X-2348
C-5
Y - 6G-9985
F-1
WW - 8W-2179 Front Wiper Motor
D - 8X-2348
B-5
Z - 6G-9986
F-6
CCC - 8X-2114 Rear Wiper Motor
V - 7T-3418
A-5
10 Contacts
CCC - 8X-2114
V - 7T-34t8
B-4
Trans Switch
WW - 8W-2179
F-6
Shift Lever Sw
9 Contacts
W - 8X-2296
E-6
Neutral/Start Control
A - 8W-7413
C-3
RELATED ELECTRICAL SERVICE MANUALS
D - 8X-2348 Title Form No.
8-5T-5218
C-2
Electronic Monitoring System (EMS) SENR2945
D - 8X-2348 Starting And Charging Systems SENR2947
D - 8X-2348
C-7
Starting Motor:
N - 5T-1527 Consist No 6N-1889
D - 8X-2348
E-1
8C-3644 SENR3581
X - 8C-4764 9X-4452 SENR4975
7 Contacts
N - 5T-1527
C-7
7T-0794 SENR3536
P - 5T-1563 (621 E)
N - 5T-1527
C-7
P-2T-1878(623E)
W - 8X-2296
D-1
Z - 6G-9986
Off Machine Switch Specification
Part No. Function Actuate Deactuate Contact Position
2M-9346 Stop Lamp Pressure 45.0 kPa MAX 5.0 kPa MIN kPa Normally Open
(6.5 psi MAX) (0.5 psi MIN)
6T-7663 Engine Oil Pressure 93.0 ± 20.8 kPa 68.9 ± 20.8 kPa Normally Open
(13.5 ± 3.0 psi) (10.0 ± 3.0 psi)
7N-9560 Conv/Retr Oil Temp (EMS) 129.4 ± 2.8°C 118.3°C MIN Normally Closed
(265.0 ± 5.0°F) (245.0°F MIN)
7T-2078 Steering Flow (EMS) 11 liter/min MAX (25.4 mm ID line) 4.9 liter/min MIN (25.4 mm ID line) Normally Open
[2.9 (U.S. gpm) MAX (1.0 in. ID line)] [1.3 (U.S. gpm) MIN (1.0 in. ID line)]
8N-1693 Engine Coolant Temp (S. Aid) 38 ± 3°C 27°C MIN Normally Closed
(100± 5OF) (81OF MIN)
8T-9792 Air Pressure (EMS) 517 ± 35 kPa 448 ± 35 kPa 1-2, Normally Open
(75 ± 5 psi) (65 ± 5 psi) 1-3, Normally Closed
9W-2343 Engine Coolant Flow (EMS) 37.0± 3.0 grams 31.0 grams MIN Normally Open
(1.3 ± 0.1 oz.) (1.1 oz. MIN)
9W-3187 Fuel Pressure (EMS) 93.0 ± 21.0 kPa 69 ± 21 kPa Normally Closed
(13.5 ± 3.0 psi) (10 ± 3 psi)
Component Location Chart
Machine
Location
Component
Schematic
Location
Machine
Location
Component
Schematic
Location
1 Alarm - Backup C-9 19 Solenoid - Up Shift A-4
A Alarm - Action (EMS) E-3 20 Starter B-3
2 Alternator B-2 21 Switch - Apron E-7
3 Batteries A-3 22 Switch - Backup Alarm F-6
B Breaker - Alternator (60A) E-5 A Switch - Blower Motor E-3
B Breaker - Blower Motor (15A) E-4 23 Switch - Brake Air Pressure E-8
B Breaker - Dome, Stop, Tail, E-4 24 Switch - Converter/Retarder Temp A-3
Panel Lamps A Switch - Panel Lamp Dimmer F-3
B Breaker - Head Lamp (15A) E-4 25 Switch - Disconnect A-3
B Breaker - Key Start (10A) E-5 A Switch - Dome Lamp F-6
4 Control - Neutral Start E-6 A Switch - Dome Lamp (Door) F-5
5 Control - Transmission F-9 A Switch - Ems Test E-3
6 Dryer - Air A-2 26 Switch - Engine Coolant Flow A-2
A Gauge - Converter/Retarder Temp D-6 27 Switch - Engine Coolant Temp (EMS) B-3
A Gauge - Engine Coolant Temp D-5 28 Switch - Engine Coolant Temp (S. Aid) A-2
A Meter - Service E-6 29 Switch - Engine Oil Pressure (EMS) B-2
A Motors - Blower F-1 ,2 30 Switch - Engine Oil Pressure B-3
A Motor - Front Washer D-8 Fuel Pump)
A Motor - Rear Washer D-8 A Switch - Flood Lamp E-3
A Motor - Front Wiper F-2 A Switch - Side Flood Lamp F-4
A Motor - Rear Wiper F-6 A Switch - Forward Horn F-5
7 Pump - Fuel Transfer B-8 32 Switch - Fuel Pressure A-2
B Relay - Main E-5 33 Switch - Head Lamp Dimmer E-8
B Relay - Start E-5 A Switch - Key Start E-4
A Resistor - Blower Motor Speed E-2 34 Switch - Parking Brake Pressure A-5
A Resistor - Panel Lamp Dimmer F-3 35 Switch - Refrigerate Pressure E-1
9 Resistor - Starter To Diagnostic Conn B-3 A Switch - Running Lamp F-4
10 Sender - Converter/Retarder Temp A-3 36 Switch - Shift Lever F-7
11 Sender - Engine Coolant Temp B-3 A Switch - Start Aid F-5
12 Sender - Tachometer A-2 37 Switch - Steering Flow A-4
13 Sender - Transmission Speed A-4 38 Switch - Stop Lamp Pressure E-8
14 Solenoid - Air Conditioner Clutch C-1 A Switch - Thermostat E-1
15 Solenoid - Apron E-7 39 Switch - Transmission A-5
16 Solenoid - Down Shift A-4 40 Switch - Transmission Hold F-7
17 Solenoid - Forward Horn E-8 A Switch - Front Wiper F-3
17 Solenoid - Differential Lock E-8 A Switch - Rear Wiper F-3
18 Solenoid - Start Aid A-2 A Tachometer D-2
A = Components located in operator's compartment.
B = Components located on the relay panel.
Resistor, Sender and Solenoid Specifications
Part No. Component Description Resistance (Ohms)¹
9G-1950 Resistor - Blower Motor Speed Overall; 2.0 ± 0.1
Tap; 1.00 ± .05
3T-3123 Resistor - Panel Lamp Dimmer 25.0 ± 0.25
6T-2217 Resistor - Starter/Diagnostic 150.0 ± 7.5
7T-8600 Solenoid - A/C Clutch 14.4 ± 0.6
7N-9719 Solenoid - Apron; Differential Lock 68
7T-9074 Solenoid - Forward Horn 55.0 ± 6.0
9G-4365 Solenoid - Start Aid 6
9P-0222 Solenoid - Up/Down Shift 26.0 ± 2.0
¹ At room temperature unless otherwise noted.
A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
3
4
5
6
8
9
10
11
12
14
15
13
16
B
1
2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
37
35
33
34
36
38
7
39
40
17
18
19
20
21
22
A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
3
4
5
6
8
9
10
11
12
14
15
13
16
B
1
2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
37
35
33
34
36
38
7
39
40
17
18
19
20
21
22
CAT
Machine Harness Connector 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
plug and 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¡
F
E
D
9
8 7
C
B
A
9 8 7
6 5 4
6 5 4
3 2
1
F
E
D
3 2 1
C
B
A
515-GY-14
119-PK
2
1
4
3
3
2
1
3
2
1
5
4
3
2
1
2
1
10
9
1
2
3
4
5
6
7
8
202-BK-18
101-RD
202-BK
L10
L31
L5
L31
L31
L32
L32
L10
L10
L10
L4
L4
L5
L9L9
L6
L25
L26
L27
L28
L29
L23
L23
L15
L15
L22
L22
L34
L34
L34
L33
L33
L33
L33
L16
L16
L28
L17
L26
L25L27L28
L29
L32 L32
L10
L10
L9
L9
L6
L6
L5L5
L5
L5
L24
L28
L19
L19
L18
L18
L35
L35
L25
L29L29
L20
L20
L26
L3
L3
L28
L25
L15
L16 L17L17
L18
L18
L35
L26
L29
L27
L27
L21
L22
L23
L19
L20
L21
L22
L23
L24
L4
L4
L3
L3
L2
L2
L2
L2
L1
L1L1
L1
5
1
4
2
3
T¡
MOTOR
L
H
1
3
2
4
OR
BR
GY
GN
125-OR-14
202-BK
608-GN
103-YL
200-BK
122-BU
1
445-GN
A-39F4337
ATCH WIRE, CABLE &
COMPONENT
A-39G0549
B-2 ATCH
2W8662
8C4764
5T1639
5T1563
B-3
8W1059
9S9312
8W2208AAA
8W3628
CABLE AS.
G
2G4177
5T0996
8W2179
5T9895
7T3418
5T1561
5T1527
5T1635
5T5218
D-7
2W8715QQ
B-2 STDQQ
B-4
C-99G6259
A-3
5T1632
E
B-3ZZ
A-3
A-3
F-4
C
NOTE B: NORMALLY CLOSED WHEN DOOR OPEN
COMPONENTS ARE SHOWN INSTALLED ON A FULLY
OPERABLE MACHINE WITH THE KEY AND ENGINE OFF
AND XMSN SHIFTER IN NEUTRAL
E-8
CIRCUIT NOT CONNECTED
CIRCUIT CONNECTED
F-4
E-4
E-1
D-1
D-1
C-5
C-5
C-7
C-7
C-7
A-9
SS
B-5
A-3
A-2
C-5
C-2
C-3
LOC
6G9986
6G9985
XX
WW
6G5258
PP
KK
JJ
EE
CC
AA
WIRE AS.
HARNESS AS.
PART NO.
IDENT
Z
Y
X
W
V
T
R
Q
P
N
M
F
D
B
A
NOTE A: NORMALLY OPEN BEFORE REFRIGERANT CHARGE
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
UNLESS OTHERWISE SPECIFIED: ALL WIRE IS 16 GAGE
CONV RETR TEMP
GAGE (TRACTOR)
4W0485
3
4
5
8
9
7
10
2
1
6
LEVER 1
LEVER 2
LEVER 3
LEVER 4
LEVER 5
NEUTRAL
GROUND
GND VERIFY
FORWARD
HORN
SOLENOID
7T9074
W
470-PU
200-BK
ID CODE 3
ID CODE 2
ID CODE 1
ID CODE 0
+10V
GND VERIFY
GND VERIFY
XMSN SP
GEAR 1
27
37
36
30
29
5
16
LEVER 5
LEVER 4
LEVER 3
LEVER 2
LEVER 1
HOLD SW
GROUND
DOWN SOL
UP SOL
GEAR 5
GEAR 4
GEAR 3
GEAR 2
+ BATTERY
15
14
13
12
11
19
18
17
20
6
7
8
2
10
9
4
3
26
25
24
23
22
21
28
35
34
33
32
31
1
322-GY
200-BK
200-BK
409-OR
470-PU
306-GN
307-OR
200-BK
126-PK
506-PU
507-WH
REAR
WASHER
7T8891
FRONT
WASHER
7T8891
MOTOR
MOTOR
LAMP
5D0019
LAMP
5D0019
LAMP
5D0019
BAT
TRANSMISSION CONTROL
9W0009
BASE
7G9730
BASE
7G9730
PANEL
LAMP
7N5876
PANEL
LAMP
7N5876
200-BK
200-BK
601-GY
601-GY
SERVICE
METER
6T7337
200-BK-
APRON SW (NOTE C)
2G3970
NEUTRAL/START
CONTROL
7X1362
200-BK
126-PK
307-OR
306-GN
409-OR
470-PU-18
OPR PANEL
NEUTRAL
GN-18
PK-18
GY-18
BU-18
YL-18
OR-18
3
BR-18
WH-18
+ BATTERY
START SW
GROUND
START RELAY
OR-18
PU-18
BK-18
GN-18
2
1
APRON (NOTE C)
SOLENOID
7N9719
200-BK
D
M
1
2 200-BK
165-YL
200-BK
717-BR
202-BK
SHIFT
LEVER SW
9W0681
REAR
WIPER
6T6216
COOLANT TEMP
GAGE (TRACTOR)
4W0483
202-BK
601-GY
126-PK
AIR PRESS
GAGE
1W3306
FORWARD
HORN SW
3T2357
NC
NO
200-BK
DOOR DOME
LAMP SW
(NOTE B)
3T3133
Z
STOP
LAMP SW
2M9346
200-BK
310-PU
602-WH
322-GY
START AID SW
3T3453
114-GN
119-PK
Q
D
2
1
604-OR
103-YL
GN
GY
BR
2
W
WW
WW
D
OR
4
408-WH
123-WH
3
4
HEAD LAMP
DIMMER SW
2H1855
OPERATOR STATION
OPERATOR STATION
610-OR-14
611-PU-14
123-WH
123-WH
441-OR
444-BU
IGN
SEND
GRD
IGN
SEND
GRD
201-BK
322-GY
200-BK
602-WH
103-YL
202-BK
716-BU
710-GN
709-OR
704-GY
703-BU
726-BU
725-GN
724-YL
723-OR
722-WH
721-BR
715-GN
714-YL
713-OR
712-WH
711-BR
708-YL
BACKUP
ALARM SW
6G4195
505-BU
504-YL
503-BR
712-WH-18
713-OR-18
714-YL-18
715-GN-18
202-BK
716-BU-18
444-BU
441-OR
711-BR-18
321-BR
200-BK
2
3
1
H
L
MOTOR
T¡
RD
BK
TACH
8T9711
OPERATOR MON
TEST SW
7N8001
LAMP
5D0019
201-BK
204-BK
ACTION LAMP
(TRACTOR)
7N1996
BASE
3T0304
(TRACTOR)
9G9813
6
7
8
9
W
324-BU
200-BK
DIFFERENTIAL
LOCK SW
3T3132
324-BU
165-YL
165-YL
HOLD SW
8D2676
202-BK
708-YL
W
W
201-BK
201-BK
415-GN
410-WH
2
1
2
1
204-BK
422-YL
421-BU
204-BK
423-PU
411-PK
165-YL
123-WH
FUSE BLOCK
9G0747
FUSE BLOCK
2S3747
101-RD
101-RD
101-RD-10
101-RD-14
101-RD-14
101-RD-10
10A
165-YL
SOLENOIDS
123-WH
FLOOD LAMPS & GAGES
24
22
14
515-GY-14
200-BK-14
200-BK-14
521-YL-14
522-WH-14
307-OR
307-OR
THERMOSTAT SW
7T9277
200-BK
200-BK
200-BK
200-BK
200-BK
126-PK
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK-8
PANEL, DOME,
STOP & TAIL
LAMP BREAKER
9G9882
409-OR
470-PU
109-OR-4
109-OR-8
109-OR-8
112-PU-14112-PU-8
112-PU-10
125-OR-14
FUEL PUMP10A
200-BK-8
REAR
WIPER SW
3T6655
FRONT
WIPER SW
3T6655
RD
RD
200-BK-14
601-GY
6
RESISTOR
9G1950
G
307-OR
306-GN
307-OR
AIR DRYER
304-WH
BLOWER SW
6P3236
3
4
5
2
1
516-GN-14
OR
BLU
BLK
RED
516-GN-14
516-GN-14
T¡
521-YL-14
517-BU-14
200-BK-14
515-GY-14
124-GN-14
DIAGNOSTIC CONNECTOR
FRONT
WIPER
6T6216
MAIN
RELAY
3T0376
101-RD-4
109-OR-4
60
ALT
BREAKER
9S0174
ATCH
9S4693
PPW
2
1
200-BK
15
112-PU-14
124-GN-14
BLOWER
MOTOR
BREAKER
6N8589
202-BK
54
21
1
HEAD LAMP
BREAKER
3T2662
-+
SIG
614-PU 600-BR
601-GY
601-GY
601-GY
200-BK
W
SIDE FLOOD
LAMP SW
3T1730
619-GN-14
102-BU-14
4
3
2
1
117-YL
103-YL
614-PU
609-YL
REAR WIPER10A
D
OPERATOR
MONITOR
3T9100
Z
YW
2
3
4
119-PK
118-GY
RUNNING
LAMP
SW
3T3826
203-BK
609-YL
614-PU
614-PU
PANEL
DIMMER
RESISTOR
3T3123
PANEL
DIMMER SW
4D1836
103-YL
12
11
10
9
8
7
6
5
4
3
2
1
103-YL
117-YL
103-YL
117-YL
10A SIDE FLOOD LAMPS
HORN
FUSE
3K8782
118-GY
119-PK
B
W P
L
H
B
B
W P
L
H
B
PANEL LAMP
7N5876
PANEL LAMP
7N5876
REFRIGERANT SW
(NOTE A)
9D6888
118-GY
310-PU
Y
SUPPL STER
FUEL PR
COOL TEMP
COOL FLOW
AIR PR
ALARM
5
4
2
3
1
W
XX W
W
W
X
X X
W
W
W W
506-PU
507-WH
35
37
500-BR
501-GN
502-OR
310-PU
34
33
31
29
27
9
30
21
20
32
18
19
10
23
7
2
25
26
11
13
12
16
15
5
1
3
8
36
28
6
17
4
470-PU-18
200-BK
708-YL
321-BR
716-BU-18
200-BK-14
515-GY-14
517-BU-14
513-OR-14
7
500-BR
501-GN
502-OR
503-BR
504-YL
505-BU
602-WH
200-BK
103-YL
310-PU
322-GY
2
1
202-BK
743-PU
KEY
BKR
9G9487
PARK BK
NEUTRAL
OPERATOR STATIONOPERATOR STATION
OPERATOR MONITOR
20
19
18
17
16
15
14
13
6
7
4
3
2
1
5
201-BK
304-WH-8
200-BK
506-PU
507-WH
24
19
123-WH
START
RELAY
9F3099
406-PU
409-OR 9
18
4
6
BASE
9D8047
BASE
9D8047
WH/RD-14
WH/RD-14
BK-14
BK-14
25
8
18
BACKUP ALARM
3
2 1
TEST
LAMP
CONV TEMP
ENG OIL PR
ALTERNATOR
GROUND
+ BATTERY
10
15
2
1
2
1
2
1
5
4
3
2
1
KEY START SW
9G7641
FLOOD LAMP SW
8D2676
BLOWER
9G8697
BLOWER
9G8693
10
16
15
9
11
22
1
20
21
14
17
6
23
5
4
2
3
12
10
13
7
6
12
8
5
4
9
1
11
10
2
7
3
101-RD-4
101-RD
119-PK
118-GY
517-BU-14
200-BK-14
610-OR-14
608-GN
308-YL
105-BR
102-BU-14
502-OR
501-GN
500-BR
113-OR
114-GN
102-BU-14
118-GY
505-BU
504-YL
503-BR
15
11
10
17
14
7
5
13
12
3
8
19
1
304-WH-8
112-PU
308-YL
304-WH
109-OR
105-BR
311-WH
310-PU
302-OR
207-BK
201-BK
415-GN
411-PK
410-WH
417-GY
201-BK
407-PK
405-GY
413-BR
412-BU
403-GN
201-BK
408-WH
419-YL
113-OR
FRONT WIPER
TRANSMISSION
10A
10A
10A
10A
10A
10A
10A
118-GY
114-GN
113-OR
102-BU-14
119-PK
MOTOR MOTOR
ST
ON
OFF
B
S
C
715-GN-18
714-YL-18
BOWL
FLOOD
LAMP
7T9094
R
MOTOR
DB-7002T3125
BOWL
FLOOD
LAMP
7T9094
604-OR
614-PU
321-BR
121-YL
323-WH
200-BK
7
2
1
4
5
3
6
608-GN
P N
P (NOTE C)
RR
T
T
W
W
608-GN
RR (NOTE D)
14
13
12
11
L32
W
121-YL
321-BR
310-PU
1
2
W
M
M
Q
D
W
202-BK
743-PU
XX
E
BACKUP
ALARM
3T1815
117-YL
614-PU
103-YL
W
601-GY
308-YL
101-RD-14
200-BK
109-OR
601-GY
121-YL
126-PK
122-BU
103-YL
118-GY
165-YL
125-OR-14
119-PK
W
W
W
202-BK126-PK
417-GY
X
X
X
W
L36
W
415-GN
L36
W
W
W
W
W
604-OR
614-PU
W
W
RIGHT
STOP/TAIL
LAMP
7X6220
LEFT
STOP/TAIL
LAMP
7X6220
W
608-GN
W
COMPARTMENT
GROUND
202-BK
L36
639-WH
L36
W
200-BK
200-BK
200-BK
(NOTE D)
D
200-BK-14
B-5018X2114CCC
00
--
640-GN
8X2982
------
B
B
B
B
B
B
START AID SWITCH
103-YL
604-OR
604-OR
614-PU
AAA
CC
C
126-PK
126-PK
201-BK
202-BK
202-BK
202-BK
200-BK
126-PK
00
00
BB
8X1994
8X1993
UNLESS OTHERWISE SPECIFIED: ALL WIRES IN A SPLICE
ARE THE SAME IDENT. NUMBER, COLOR AND 16 GAGE
D
D
D
D
WW
WW
C
Z
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
L35
W
W
A
A
A
A
A
A
A
A
A
A
200-BK
200-BK
200-BK
200-BK
A
A
200-BK
602-WH
L4
601-GY
601-GY
601-GY
200-BK
200-BK
200-BK
200-BK
T
639-WH
640-GN
604-OR
614-PU
STOP/TAIL
LAMP CONTROL
7X1670
LEFT LAMP
RIGHT LAMP
STOP IN
TAIL IN
WH
GN
OR
PU
713-OR-18
201-BK 201-BK
201-BK
AIR SW
8T9792
DIFFERENTIAL
LOCK SOLENOID
7N9719
201-BK
408-WH
L32
D
DOME
LAMP
8C9678
602-WH
103-YL
200-BK
3
2
1
BK
YL
WH
403-GN
601-GY
601-GY
L4
601-GY
200-BK
L9
L32
123-WH
123-WH
201-BK
403-GN20
16
2
12V BATTERY
3T5760
12V BATTERY
3T5760
CCBB
BB
AA
RRP
GN-14
GN-14
712-WH-18
513-OR-14
522-WH-14
123-WH
123-WH
123-WH
123-WH
123-WH
123-WH
101-RD
WW
103-YL
202-BK
202-BK
202-BK
202-BK
202-BK
202-BK
202-BK
200-BK
202-BK
201-BK
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK
200-BK
121-YL
321-BR
200-BK-14
515-GY-14
200-BK
323-WH
R
2
1
601-GY
601-GY
601-GY
321-BR
N
NP
PR
D
D
708-YL
200-BK
711-BR
712-WH
713-OR
714-YL
715-GN
202-BK
716-BU
7
8
10
1
2
3
4
5
9
6
200-BK
323-WH
321-BR
121-YL
2
1
4
5
3
6
601-GY
601-GY
200-BK
200-BK-14
200-BK
200-BK
200-BK
FUEL
PUMP
1W4279
BK/PK-14
BK-14
D
2
1
608-GN
323-WH
200-BK
BK
RD
PU
NOTE D: FOR THE 623E ONLY
NOTE C: FOR THE 621E ONLY
D
C
D
608-GN
6
3
5
4
1
2
7 7
6
3
5
4
1
2
2
1
01
8X2296
A-9
8X2348
C-72T1910
C-72T1878
T
R
00
01
01
02
01
A-200
00
00
03
07
00
00
02
02
00
04
01
01
00
03
8X2006
R
02
01
05
03
05
C
D
C
NOTE
00
00
02
P
8W7413
03
CHG
01
203-BK
STARTER
6N1889 STD
3T8947 ATCH
CONV RETR SENDER
(TRACTOR)
6N5926
CONV RETR SW
(TRACTOR)
7N9560
12V BATTERY
3T5760
12V BATTERY
3T5760
LO BEAM
HEAD LAMP
9W0051
LO BEAM
HEAD LAMP
9W0051
2
1
614-PU
604-OR
200-BK
T
403-GN
200-BK
200-BK
200-BK
470-PU
RD-00
BB
604-OR
614-PU
321-BR
121-YL
323-WH
200-BK
BK-00
BK-00
507-WH
506-PU
DISCONNECT SW
7N0718
611-PU-14
619-GN-14
609-YL
A
101-RD-4
NEG POS
202-BK
608-GN
470-PU
201-BK
203-BK
ZZ
207-BK
619-GN-14
SIDE FLOOD
LAMP
7T9094
SIDE FLOOD
LAMP
7T9094
203-BK
BK-00
BK-00
RESISTOR
6T2217
TO ENG
BLOCK
HI BEAM
HEAD LAMP
9W0052
HI BEAM
HEAD LAMP
9W0052
203-BK
445-GN
103-YL
614-PU
609-YL
609-YL
202-BK
301-BU
NEG POS NEG POS
SS
2
1
302-OR
T¡
T¡
EE
JJ
D
AA
506-PU
507-WH
201-BK
408-WH
419-YL
322-GY
126-PK
122-BU
200-BK
121-YL
608-GN
608-GN
417-GY
323-WH
TO
FRAME
G S
MTR BAT
MOTOR
AUX START
RECEPTACLE
BK-00
RD-00
BK-00
BK-6
BK-00
RD-00
304-WH-8
200-BK-8
200-BK
451-BR
450-YL
711-BR-18
412-BU
COOLANT SENDER
6N5926
COOLANT SW
7N9785
323-WH
125-OR-14
CC
407-PK
406-PU
441-OR
444-BU
R
201-BK
611-PU-14
310-PU
311-WH
122-BU
201-BK
NEG POS
200-BK
451-BR
450-YL
A/C CLUTCH
SOLENOID
7T8600
6
7
513-OR-14
513-OR-14
522-WH-14
522-WH-14
521-YL-14
516-GN-14
200-BK-14
517-BU-14
515-GY-14
521-YL-14
COOLANT SW
9W2343
TACHOMETER
SENDER
7T6945
BK-18
BK-18
FUEL SW
9W3187
5
323-WH
6
7
1
5
4
3
2
323-WH
125-OR
2
1
125-OR-14
ENGINE OIL SW
6T7663
ENGINE OIL SW
6T7663
BK
RD
BU
201-BK
419-YL
PARKING
BRAKE SW
8T9792
STEERING SW
7T2078
W/O STEERING SW
CONNECT PLUG F TO
RECEPTACLE F
417-GY
201-BK
F
F F
2
1
2
1
BK
BK 2
1
417-GY
201-BK
CCC
CCC
CCC
D
CCC
D
CCC
TRANSMISSION
TRANSMISSION
SPEED SENDER
7T6337
703-BU
704-GY
201-BK
417-GY
419-YL
TRANSMISSION SW
(TRACTOR)
9W1409
1
DOWN SHIFT
SOLENOID
9P0222
UP SHIFT
SOLENOID
9P0222
TRANSMISSION
743-PU
422-YL
421-BU
423-PU
204-BK
CCC
202-BK-18
726-BU-18
725-GN-18
724-YL-18
723-OR-18
722-WH-18
721-BR-18
E
F
H
D
CCC
CCC
CCC
CCC
GEAR 1
GEAR 2
GEAR 3
GEAR 4
GEAR 5
GROUND
GND VERIFY
10
9
8
7
6
5
4
3
2
202-BK
J
I
G
AD
516-GN-14
200-BK
4
3
2
1
START AID
SOLENOID
9G4365
2
1
BD
C
B
A
GROUND
SIGNAL
+V
C
B
A
CUTTING
EDGE
FLOOD
LAMP
7T9094
V
V
COOLANT
SW
8N1693
T
203-BK
BC
203-BK
610-OR-14
611-PU-14
619-GN-14
610-OR-14
310-PU
311-WH
QQ
ALTERNATOR
5S9088 STD
8N0999 ATCH
T¡
T
201-BK
405-GY
400-GN
207-BK
619-GN-14
400-GN
D
200-BK-14
B
726-BU
725-GN
724-YL
723-OR
722-WH
721-BR
710-GN
1
2
1
2
608-GN
202-BK
726-BU
725-GN
724-YL
723-OR
722-WH
721-BR
709-OR
710-GN
202-BK
202-BK
202-BK
709-OR
703-BU
704-GY
A
KK
B
A
517-BU-14
515-GY-14
200-BK-8
109-OR-4
451-BR
450-YL
441-OR
444-BU
311-WH
310-PU
412-BU
403-GN
201-BK
413-BR
405-GY
407-PK
406-PU
101-RD-4
304-WH-8
302-OR
2
1
407-PK
413-BR
405-GY
201-BK
109-OR-4
BK-6
403-GN
BK-18
BK-18
2
1
2
1
AIR DRYER
2G2159
413-BR
311-WH
A
122-BU
311-WH
310-PU
201-BK
AAA
610-OR-14
THIS SCHEMATIC IS FOR THE 621E/623E WHEEL
TRACTOR SCRAPER ( 9X4944 CHG 00 )
ALT
+
R
ACTION ALARM
GRN
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.
EMS CIRCUIT.
PANEL LAMP CIRCUIT.
WIPER/WASHER CIRCUIT.
HEATER AND AIR CONDITIONER CIRCUIT.
GROUND CIRCUIT.
START AID CIRCUIT.
TRANSMISSION CONTROL CIRCUIT.