SENR5821 May 1993
F
8
24 1614 19 18 12 13 15
A
D
1
20
11 23 9
26
22 7 21 2
17
6 1
5 27
B
10
C
25
4
3
Harness Connector Location Chart Machine Location
Connectors
B - 9R-8619 E - 100-4971
1 E
E - 100-4971 D - 100-4969
B-4
C
E - 100-4971 H - 9R-8623
B-7, B-8
1 E
E - 100-4971 R - 6Y-2167
B-4
*
E - 100-4971 Diode As.
D-5
D
E - 100-4971 L - 9R-8624
E-4
*
E - 100-4971 Shift Control
C-5
C
A - 9R-9554 K - 9R-9555
B-7
2
*
A - 9R-9554 Front Wiper Motor
D-3
22
*
A - 9R-9554 Rear Wiper Motor
E-9
1 E
E - 100-4971 D - 100-4969
B-4
*
E - 100-4971 Shift Control
C-4
1 E
E - 100-4971 G - 103-5683
A-4
*
E - 100-4971 Turn/Hazard Switch
E-3
C
E - 100-4971 H - 9R-8623
10 Contacts
A
8 Contacts
F
B C
24
11 12 16 19 1 18 13 15
1
26
27
20
10
25 14
7 21 23
6 8
3
9
4
17
6 Contacts
5
4 Contacts
Wire Color
101 102 103 105 109 112 113 116 118 119 120 121 122 123 124 126 128 143 157 161 194
RD BU YL BR OR PU OR BR GY PK YL YL BU WH GN PK PK BR YL PK GN
200
BK
301 304 306
BU WH GN
307 308 309 310 311 321 322 326
OR YL GY PU WH BR GY PU
405 406 415 417 419 441 443 447 450 483
GY PU GN GY YL OR YL PK YL BR
Power Distribution Circuits BAT HD LMP AUX CKT KEY SW ALT OUTPUT (+) TERM. MAIN POWER RELAY OUTPUT OPR MON PANEL AUX CKT AUX CKT AUX CKT AUX CKT BACKUP ALARM TO LAMP AUX CKT AUX CKT A/C XMSN CONT AUX CKT AUX CKT AUX CKT AUX CKT AUX CKT Ground Circuits MAIN CHASSIS Basic Machine Circuits STARTER NO. 1 SOL STARTER RELAY NO. 1 OUTPUT STARTER RELAY COIL TO NEUT START SW OR KEY SW KEY SW TO NEUT START SW MAIN POWER RELAY COIL ALTERNATOR REGULATOR TERM. START AID SW TO START AID SOL START AID SOL TO TEMP SW BCKP ALARM LAMP TRAVEL ALARM WARNING HORN (FORWARD) KEY SW “C” TERM. Monitoring Circuits OPR MON OIL PRESS. (LO SETTING) OPR MON COOLANT TEMP OPR MON TEST SW PRIMARY STER SW OPR MON PARKING BRAKE ENG COOLANT TEMP GAGE POWER TRAIN TEMP GAGE FUEL LEVEL GAGE TACH SENDER (+) BRAKE FLUID LEVEL
Wire Number
Wire Color
500 501 502 503 504 505 506 513 515 516 517 520 521 522 536 552 568
BR GN OR BR YL BU PU OR GY ON BU WH YL WH WH WH GN
603 604 605 606 607 608 610 614 617 618 620 630 634 639 640
PK OR YL GY PK GN OR PU BR YL WH GY WH WH GN
751 752 754 755 762 766 900 901 921 922 923 924 925 926
GN YL BU OR YL GN PU WH WH BR GY GN YL BU
Description Accessory Circuits WIPER - FRONT (PARK) WIPER - FRONT (LO) WIPER - FRONT (HI) WIPER - REAR (PARK) WIPER - REAR (LO) WIPER - REAR (HI) WASHER - FRONT A/C COMPRESSOR/REFRIGERANT PRESS. SW BLOWER MOTOR (HI) BLOWER MOTOR (MEDIUM) BLOWER MOTOR (LO) OPR A/C SW TO THERMOSTAT/FUSE A/C SW TO REFRIGERANT SW A/C CLUTCH TO THERMOSTAT SW HAZARD SW TO TURN SW FOUR WHEEL DRIVE SOL WARNING BUZZER TO DIODES Lighting Circuits ROTARY BEACON STOP LAMP TURN LAMP - LEFT TURN LAMP - RIGHT FLOOD LAMP - FRONT FLOOD LAMP - REAR HEAD LAMP BASIC PARK/TAIL/DASH LAMP TAIL/POSITION LAMP - LEFT (ROAD PKG)/WIDTH TAIL/POSITION LAMP - RIGHT (ROAD PKG)/ WIDTH FLOOD LAMP - FRONT (ENG. FLOOD LAMP) FLOOD LAMP REAR (ATTACH) HEAD LAMP SW TO WORK/HEAD LAMP JUMPER LEFT HAND STOP/TAIL LAMP RIGHT HAND STOP/TAIL LAMP Control Circuits XMSN SHIFT SOL NO. 1 OR 3 XMSN SHIFT SOL NO. 2 XMSN SHIFT SOL NO. 3 OR 1 XMSN SHIFT SOL NO. 4 OR 5 BUCKET POSITIONER SOL SW XMSN DISCONNECT SOL XMSN SHIFT SOL NO. 5 OR 4 XMSN SHIFT SOL NO. 6 XMSN SOL NO 1 OR 3 RETURN XMSN SOL NO 2 RETURN XMSN SOL NO 3 OR 1 RETURN XMSN SOL NO 4 OR 5 RETURN XMSN SOL NO 5 OR 4 RETURN XMSN SOL NO 6 RETURN
Machine Location 1 D
5BL1-UP
B-7, B-8
C = Connector in right console. D = Connector in front console/dash.
Component Location Chart Alarm - Backup
Schematic Location B-9
Machine Location 10
Solenoid - Bucket Positioner
Schematic Location A-5
Alarm - Action
D-5
11
Solenoid - Engine Shutdown
E-2
2
Alternator
B-2
12E
Solenoid - Fourth Gear (No. 3)
C-2
3
Batteries
A-3
13E
Solenoid - Forward (No. 2)
C-2
C
Breaker - Running Lamp
B-8
14
Solenoid - Front Drive
C-3
A
Control - Shifter
C-5
15E
Solenoid - Reverse (No. 1)
C-2
D
Diode As.
D-5
16E
Solenoid - Second Gear (No. 5)
C-2
C
Flasher
C-7
17
Solenoid - Start Aid
A-2
C
Fuses
C-9
18E
Solenoid - Third Gear (No. 6)
C-2
B
Gauge - Converter Temperature
D-8
19E
Solenoid - First Gear (No. 4)
C-2
B
Gauge - Coolant Temperature
D-8
B
Switch - Beacon
D-7
B
Gauge - Fuel
D-9
F
Switch - Blower (A/C)
E-5
B
Gauge - Tachometer
D-9
F
Switch - Blower (Heater)
D-4
Component
Component
4
Horn - Forward
A-2
D
Switch - Brake (Stop Light)
E-4
B
Meter - Service
D-8
20
Switch - Brake Pressure
C-2
B
Meter - Volt
D-8
21
Switch - Coolant Temperature
C-2
F
Motor - Blower (A/C)
E-6
22
Switch - Coolant Temperature (Start Aid)
C-2
F
Motor - Blower (Heater)
C-4
23
Switch - Engine Oil Pressure
C-2
A
Motor - Fan
E-7
D
Switch - Forward Horn
D-3
A
Motor - Front Wiper
E-3
D
Switch - Front Drive
D-3
A
Motor - Rear Wiper
E-9
B
Switch - Front Wiper
C-6
5
Motor - Starter
A-2
B
Switch - Front Flood
E-7
C
Relay - ACC
C-7
B
Switch - Key Start
C-7
C
Relay - A/C
C-9
24
Switch - Parking Brake
D-6
C
Relay - Cab
C-9
25
Switch - Primary Steering Pressure
C-3
C
Relay - Lamp Check
C-7
B
Switch - Rear Flood Lamp
E-7
C
Relay - Main
C-8
B
Switch - Rear Wiper
C-6
C
Relay - Start
B-8
26
Switch - Refrigerant
F-1
C
Resistor - Alternator Field
C-7
27
Switch - Return To Dig
A-3
F
Resistor - Blower Motor Speed (A/C)
E-5
B
Switch - Running Lamp
D-7
F
Resistor - Blower Motor Speed (Heater)
D-3
B
Switch - Start Aid
D-7
6
Sender - Converter
B-2
F
Switch - Thermostat
D-5
7
Sender - Coolant Temperature
C-1
A
Switch - Transmission Neutralizer
B-6
8
Sender - Fuel
F-4
D
Switch - Turn Signal/Hazard
E-3
9
Solenoid - Air Conditioner Clutch
D-1
A
Pressure Symbol
Temperature Symbol
Level Symbol
Flow Symbol
Function
6T2665
Coolant Temperature
8T8640
Transmission Pressure
9D6888
Refrigerant Pressure
9W1520
Engine Coolant Temp (Start Aid)
9W4139
Brake Pressure
N.C. Normally Closed. N.O. Normally Open.
Actuate
107.2 ± 2.8°C (225 ± 5°F) 1206 kPa MAX (175 psi MAX) 234 kPa MAX (34 psi MAX) 37.8 ± 2.8°C (100 ± 5°F) 13780 kPa MAX (2000 psi MAX)
Deactuate
93°C MIN (196°F MIN) 700 ± 103 kPa (100 ± 15 psi) 152 kPa MIN (22 psi MIN) 26.7°C MIN (80°F MIN) 10335 ± 689 kPa (1500 ± 99 psi)
Contact Position Normally Closed Contact 1 - 3 (N.C.) Contact 1 - 2 (N.O.) Normally Open Normally Closed Normally Closed
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.
Part No.
Resistance (Ohms)¹
Resistor - Alternator
8C4110
22 ± 1.1
Resistor - Blower Motor Speed
7T3828
Overall 1.0 ± .1; Tap 0.5 ± .05
Solenoid - A/C Clutch
8T8812
3.5 ± 0.15
Solenoid - Bucket Positioner
3E8620
21.8 ± 1.0
Solenoid - Front Drive
6T6885
8.9 ± .3
Solenoid - Shutdown
8C3662
Start 0.386 ± 10%; Stop 2.58 ± 10%
Solenoid - Start Aid
3T9493
1.5
A
A 325-PK-14
Pin
Normally closed switch that will open with an increase of a specific condition.
AA 1
9X-1123 325-PK-14
Wire Color
Socket
2
200-BK-14
Circuit Number Identification
Normally closed switch that is open due to an applied condition, and will close again with a specific decrease in that condition.
Wire Gauge
Electrical Schematic Symbols And Definitions
The circle indicates that the component has screw terminals and a wire can be disconnected from it.
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.
No circle indicates that the wire cannot be disconnected from the component.
This indicates that the component does not have a wire connected to ground. It is grounded by being fastened to the machine. Resistor and Solenoid Specifications
Component Part Number
Single Wire Connector C
F = Components in operator compartment - left console.
¹ At room temperature.
2
Typical representation of a Sure-Seal connector. The plugand receptacle contain both pins and sockets.
Wire, Cable, or Harness Assembly Identification
E = Components in operator compartment - under floor plate.
Component
Typical representation of a Deutsch connector. The plug contains all sockets and the receptacle contains all pins.
Pin or Socket Number
This indicates that the component has a wire connected to it that is connected to ground.
D = Components in front console/dash.
1 2
1 2
Receptacle
Plug
T
T
C = Components on relay panel (inside right console).
AA 1
B = Components in operator compartment - right console.
Part No.
Harness And Wire Electrical Schematic Symbols
Electrical Schematic Symbols And Definitions
A = Components in operator compartment.
Off Machine Switch Specifications
Printed in U.S.A.
© 1993 Caterpillar All Rights Reserved
E = Connector under floor plate.
Wire Description Chart Description
A-8
* = Connector is located at the component.
Machine Harness Connector And Component Locations
Wire Number
Schematic Location
C 12 Contacts
D
Harness And/Or Components
446B Backhoe Loader Electrical System
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. 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.