Wire Number
Wire Color
101
RD
102
Wire Description
Connector Location
Wire Number
Wire Color
BAT
447
PK
FUEL LEVEL GAGE
BU
HD LMP
450
YL
TACH SENDER (+)
103
YL
AUX CKT
483
BR
BRAKE FLUID LEVEL
105
BR
KEY SW
109
OR
ALT OUTPUT (+) TERM.
500
BR
WIPER - FRONT (PARK)
112
PU
MAIN POWER RELAY OUTPUT
501
GN
WIPER - FRONT (LO)
113
OR
OPR MON PANEL B+ SWITCHED
502
OR
WIPER - FRONT (HI)
116
BR
AUX CKT
503
BR
WIPER - REAR (PARK)
118
GY
AUX CKT
504
YL
WIPER - REAR (LO)
119
PK
AUX CKT
505
BU
WIPER - REAR (HI)
120
YL
AUX CKT
506
PU
WASHER FRONT
121
YL
BACKUP ALARM TO LAMP
513
OR
122
BU
AUX CKT
515
GY
A/C COMPRESSOR/REFRIGERANT PRESS. SW BLOWER MOTOR (HI)
123
WH
AUX CKT
516
GN
BLOWER MOTOR (MEDIUM)
124
GN
A/C
517
BU
BLOWER MOTOR (LO)
126
PK
XMSN CONT
520
WH
OPR A/C SW TO THERMOSTAT/FUSE
128
PK
AUX CKT
521
YL
A/C SW TO REFRIGERANT SW
143
BR
AUX CKT
522
WH
A/C CLUTCH TO THERMOSTAT SW
157
YL
AUX CKT
536
WH
HAZARD SW TO TURN SW
161
PK
AUX CKT
552
WH
FOUR WHEEL DRIVE SOL
194
GN
AUX CKT
568
GN
WARNING BUZZER TO DIODES
576
PK
WIPER - AUX (LO)
577
PU
WIPER - AUX (HI)
A512
GN
REAR INTERRUPT SW TO WIPER MOTOR
Description Power Circuits
Description
Connectors
Monitoring Circuits (Cont'd)
Machine Location
200
BK
Main Chassis
265
BK
AUX
270
BK
AUX Basic Machine Circuits
603
PK
ROTARY BEACON
303
BR
KEY SW ACC POSITION
604
OR
STOP LAMP
304
WH
STARTER RELAY NO. I OUTPUT
605
YL
TURN LAMP - LEFT
606
GY
TURN LAMP - RIGHT
607
PK
FLOOD LAMP - FRONT
8 Contacts
Schematic Location
C
E - 9R-8633 H - 9R-8623
C
E - 9R-8633 H - 9R-8623
B-8
1 E
D - 9R-8621 E - 9R-8633
B-4
*
E - 9R-8633 Diode As.
D-5
D
E - 9R-8633 L - 9R-8624
E-4
C
A -9R-9554 K -9R-9555
B-7
*
A - 9R-9554 Front Wiper Motor
D-3
*
A - 9R-9554 Rear Wiper Motor (Upper)
E-9
C
B - 9R-8620 E - 9R-8633
A-8
D
E - 9R-8633 F - 9R-8626
E-2
1 E
E - 9R-8633 G - 9R-8843
A-4
*
E - 9R-8633 Turn/Hazard Switch
E-3
*
F-9R-8626 Head/Position Turn Lamp
12 Contacts
Accessory Circuits
Ground Circuits
Harness And/Or Components
6 Contacts
Connectors
Machine Location
Harness And/Or Components
Schematic Location
C
E - 9R-8633 H - 9R-8623
B-8
2
E - 9R-8633 KK - 9R-9568
A-9
3
E - 9R-8633 KK - 9R-9568
F-9
B-7 4 Contacts
A-2,F-2
* = Connector is located at the component. C = Connector is in right console.
416B, 426B, 428B, 436B and 438B Backhoe Loaders with European Cab Electrical System
D = Connector is in front console/dash. E = Connector is in operator compartment - under floor plate.
Lighting Circuits
308
YL
STARTER RELAY COIL TO NEUT START SW OR KEY SW KEY SW TO NEUT START SW OR VMIS SENSOR MODULE MAIN POWER RELAY COIL
608
GN
FLOOD LAMP - REAR
309
GY
ALTERNATOR REGULATOR TERM.
610
OR
HEAD LAMP BASIC
310
PU
START AID SW TO START AID SOL
611
PU
HEAD LAMP HI
321
BR
BCKP ALARM LAMP TRAVEL ALARM
614
PU
PARK/TAIL/DASH LAMP
8C4110
Resistor - Alternator
322
GY
WARNING HORN (FORWARD)
617
BR
7T3828
Resistor - Blower Motor Speed
367
BU
WARNING HORN (REAR)
618
YL
3E7703
Solenoid - A/C Clutch
3.5 ± 0.15
3E8620
Solenoid - Bucket Positioner
21.8 ± 1.0
372
GN
STABILIZER LOCK VALVE RTN
619
GN
TAIL/POSITION\LAMP - LEFT (ROAD PKG)/WIDTH TAIL/POSITION LAMP - RIGHT (ROAD PKG)/WIDTH HEAD LAMP LO
3E7507
Solenoid - Front Drive/Trans Neutralizer
7.7 ± .77
620
WH
FLOOD LAMP - FRONT (ENG. FLOOD LAMP)
3E8621
Solenoid - Sideshift Lock
FLOOD LAMP REAR (ATTACH)
306
GN
307
OR
Monitoring Circuits
Resistor, Sender and Solenoid Specifications
Part No.
405
GY
OPR MON OIL PRESS. (LO SETTING)
630
GY
406
PU
OPR MON COOLANT TEMP
634
WH
415
GN
OPR MON TEST SW
419
YL
OPR MON PARKING BRAKE
737
GN
SWITCHING GEAR CODE 5 FRONT
441
OR
ENG COOLANT TEMP GAGE
762
YL
BUCKET POSITIONER SOL SW
443
YL
POWER TRAIN TEMP GAGE
766
GN
XMSN DISCONNECT SOL
776
YL
BRAKE RELEASE RELAY CONT
SENR5813 February 1993
Component Description
Resistance (Ohms)¹ 22 ± 1.1
416B: 8SG1-UP
428B: 7EJ1-UP
426B: 5YJ1-UP
426B: 6MJ1-UP
438B: 3KK1-UP
Overall 1.0 ± .1; Tap 0.5 ± .05
10.5
¹ At room temperature.
HEAD LAMP SW TO WORK/HEAD LAMP JUMPER Control Circuits
Part No.
Off Machine Switch Specification
Function
6T2665
Coolant Temperature
9D6888
Refrigerant Pressure
Actuate
107.2 ± 2.8°C (225 ± 5°F) 234 kPa MAX (34 psi MAX)
Deactuate
Contact Position
93°C MIN (196°F MIN) 152 kPa MIN (22 psi MIN)
Normally Closed Normally Open
Printed in U.S.A.
© 1993 Caterpillar All Rights Reserved
Alarm - Backup Alarm - Action
D-5
A
Solenoid - Bucket Positioner
A-4
13
Alternator
B-1
2
Solenoid - Engine Shutdown
D-2
14
Batteries
F-5
3
Solenoid - Front Drive
B-2
15
Breaker - Running Lamp
B-8
C
Solenoid - Lift
C-2
19
Component
Machine Location 1
Component Solenoid - Air Conditioner Clutch
Schematic Location D-1
Machine Location 12
Coil - Start Aid
B-2
7
Solenoid - Sideshift Lock
C-9
1
Diode As.
D-5
D
Solenoid - Tilt
D-1
21
Flasher
C-7
D
Solenoid - Transmission Neutralizer
C-2
18E
C-9, E-5
C
Switch - Backup Alarm/Parking Brake
C-2
17E
Gauge - Converter Temperature
D-8
B
Switch - Beacon
D-7
B
Gauge - Coolant Temperature
D-8
B
Switch - Blower (A/C)
E-5
A
Gauge - Fuel
D-9
B
Switch - Blower (Heater)
D-4
A
Fuse - Holders
Harness And Wire Electrical Schematic Symbols
Electrical Schematic Symbols And Definitions
Component Location
Schematic Location B-9
Gauge - Tachometer
D-9
B
Switch - Brake Fluid Level
C-4
27
Horn - Forward
A-1
4
Switch - Coolant Temperature
D-2
20
Horn - Rear
B-9
1
Switch - Dimmer
D-5
A
Meter - Service
D-8
B
Switch - Engine Oil Pressure
D-2
22
A
AA
T
Pressure Symbol
Temperature Symbol
Level Symbol
Flow Symbol
Typical representation of a Deutsch connector. The plug contains all sockets and the receptacle contains all pins.
Receptacle
Plug
1 2
1 2
1
2
6
3
Pin or Socket Number
2 5
D
27
A
18 1
15 8
B
D-8
B
Switch - Forward Horn
C-3
A
Motor - Blower (A/C)
E-5
A
Switch - Front Drive
C-3
A
Motor - Blower (Heater)
C-4
A
Switch - Front Wiper
C-6
B
Motor - Fan
E-7
A
Switch - Front Flood
E-7
B
Motor - Front Wiper
E-3
A
Switch - Head Lamp/Front Flood
D-6
B
Motor - Rear Wiper (Lower)
E-8
A
Switch - Key Start
C-7
B
Motor - Rear Wiper (Upper)
E-9
A
Switch - Loader Lock
C-5
13
Motor - Starter
E-2
5
Switch - Neutral/Start
C-2
23
Motor - Windshield Washer
F-3
6
Switch - Parking Brake
D-5
A
Relay - ACC
C-7
C
Switch - Rear Flood Lamp
E-7
B
Relay - A/C
B-9
C
Switch - Rear Horn
D-8
A
Relay - Cab
C-9
C
Switch - Rear Lower Wiper
E-6
B
Relay - Lamp Check
B-7
C
Switch - Rear Upper Wiper
C-6
B
Relay - Loader Lock
C-7
C
Switch - Refrigerant
F-1
26
B
Relay - Main
C-8
C
Switch - Return To Dig
D-1
21
C
Relay - Start
B-8
C
Switch - Running Lamp
D-6
B
Resistor - Alternator Field
C-7
C
Switch - Side Lock
B-9
A
Resistor - Blower Motor Speed (A/C)
E-5
A
Switch - Start Aid
D-7
B
Resistor - Blower Motor Speed (Heater)
D- 4
A
Switch - Thermostat
D-5
A
Sender - Converter
B-2
8
Switch - Turn Signal/Hazard
E-3
A
Sender - Coolant Temperature
C-1
9
Switches - Brake (Stop Light)
D-4, E-4
27D
Sender - Fuel
A-6
10
Switches - Transmission Neutralizer
B-6,C-S
A
12
22
14
26
9
4 21
20
19
Wire, Cable, or Harness Assembly Identification
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.
10
C
A
A 325-PK-14
Pin
AA 1
2
Normally closed switch that is open due to an applied condition, and will close again with a specific decrease in that condition. A
27 18
1
7
13
14
17 1
10
19
8
23
5
FUSE - A component in an electrical circuit that will open the circuit if too much current flows through it.
12 9
21
No circle indicates that the wire cannot be disconnected from the component.
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.
2 22
26
15 3
Wire Gauge
Electrical Schematic Symbols And Definitions
4 20
200-BK-14
Circuit Number Identification
The circle indicates that the component has screw terminals and a wire can be disconnected from it. D
9X-1123 325-PK-14
Wire Color
Socket
Normally closed switch that will open with an increase of a specific condition.
3
Component Part Number
Single Wire Connector
2
13
C
Meter - Volt
7
23
17
3
2
Typical representation of a Sure-Seal connector. The plugand receptacle contain both pins and sockets.
6
This indicates that the component has a wire connected to it that is connected to ground.
T
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.
A = Components in operator compartment. B = Components in operator compartment - Right console. C = Components on relay panel (inside right console). D = Components in front console/dash. E = Components in operator compartment - under floor plate.
Machine Harness Connector and Component Locations
This indicates that the component does not have a wire connected to ground. It is grounded by being fastened to the machine.
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. 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.