446B BACKHOE ELECTRICAL SYSTEM SCHEMATIC

Machine
Location
Component
Schematic
Location
Machine
Location
Component
Schematic
Location
1 Alarm - Backup B-9 10 Solenoid - Bucket Positioner A-5
D 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
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 = 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.
F = Components in operator compartment - left console.
Component Location Chart
Connectors
Machine
Location
Harness And/Or Components
Schematic
Location
C
B - 9R-8619
E - 100-4971
A-8
E - 100-4971
D - 100-4969
B-4
C
E - 100-4971
H - 9R-8623
B-7, B-8
10 Contacts
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
*
A - 9R-9554
Front Wiper Motor
D-3
*
A - 9R-9554
Rear Wiper Motor
E-9
E - 100-4971
D - 100-4969
B-4
*
E - 100-4971
Shift Control
C-4
E - 100-4971
G - 103-5683
A-4
*
E - 100-4971
Turn/Hazard Switch
E-3
4 Contacts C
E - 100-4971
H - 9R-8623
B-7, B-8
* = Connector is located at the component.
C = Connector in right console.
D = Connector in front console/dash.
E = Connector under floor plate.
Harness Connector Location Chart
12 Contacts
8 Contacts
6 Contacts
Resistor and Solenoid Specifications
Component 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
¹ At room temperature.
Wire Description Chart
Number
Color
Description
Number
Wire
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
OPR MON PANEL
506
PU
WASHER - FRONT
116
BR
AUX CKT
513
OR
A/C COMPRESSOR/REFRIGERANT PRESS. SW
118
GY
AUX CKT
515
GY
BLOWER MOTOR (HI)
119
PK
AUX CKT
516
ON
BLOWER MOTOR (MEDIUM)
120
YL
AUX CKT
517
BU
BLOWER MOTOR (LO)
121
YL
BACKUP ALARM TO LAMP
520
WH
OPR A/C SW TO THERMOSTAT/FUSE
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
536
WH
HAZARD SW TO TURN SW
126
PK
XMSN CONT
552
WH
FOUR WHEEL DRIVE SOL
128
PK
AUX CKT
568
GN
WARNING BUZZER TO DIODES
143
BR
AUX CKT
Lighting Circuits
157
YL
AUX CKT
603
PK
ROTARY BEACON
161
PK
AUX CKT
604
OR
STOP LAMP
194
GN
AUX CKT
605
YL
TURN LAMP - LEFT
Ground Circuits
606
GY
TURN LAMP - RIGHT
200
BK
MAIN CHASSIS
607
PK
FLOOD LAMP - FRONT
Basic Machine Circuits
608
GN
FLOOD LAMP - REAR
301
BU
STARTER NO. 1 SOL
610
OR
HEAD LAMP BASIC
304
WH
STARTER RELAY NO. 1 OUTPUT
614
PU
PARK/TAIL/DASH LAMP
306
GN
STARTER RELAY COIL TO NEUT START
617
BR
TAIL/POSITION LAMP - LEFT (ROAD PKG)/WIDTH
SW OR KEY SW
618
YL
TAIL/POSITION LAMP - RIGHT (ROAD PKG)/ WIDTH
307
OR
KEY SW TO NEUT START SW
620
WH
FLOOD LAMP - FRONT (ENG. FLOOD LAMP)
308
YL
MAIN POWER RELAY COIL
630
GY
FLOOD LAMP REAR (ATTACH)
309
GY
ALTERNATOR REGULATOR TERM.
634
WH
HEAD LAMP SW TO WORK/HEAD LAMP JUMPER
310
PU
START AID SW TO START AID SOL
639
WH
LEFT HAND STOP/TAIL LAMP
311
WH
START AID SOL TO TEMP SW
640
GN
RIGHT HAND STOP/TAIL LAMP
321
BR
BCKP ALARM LAMP TRAVEL ALARM
Control Circuits
322
GY
WARNING HORN (FORWARD)
751
GN
XMSN SHIFT SOL NO. 1 OR 3
326
PU
KEY SW “C” TERM.
752
YL
XMSN SHIFT SOL NO. 2
Monitoring Circuits
754
BU
XMSN SHIFT SOL NO. 3 OR 1
405
GY
OPR MON OIL PRESS. (LO SETTING)
755
OR
XMSN SHIFT SOL NO. 4 OR 5
406
PU
OPR MON COOLANT TEMP
762
YL
BUCKET POSITIONER SOL SW
415
GN
OPR MON TEST SW
766
GN
XMSN DISCONNECT SOL
417
GY
PRIMARY STER SW
900
PU
XMSN SHIFT SOL NO. 5 OR 4
419
YL
OPR MON PARKING BRAKE
901
WH
XMSN SHIFT SOL NO. 6
441
OR
ENG COOLANT TEMP GAGE
921
WH
XMSN SOL NO 1 OR 3 RETURN
443
YL
POWER TRAIN TEMP GAGE
922
BR
XMSN SOL NO 2 RETURN
447
PK
FUEL LEVEL GAGE
923
GY
XMSN SOL NO 3 OR 1 RETURN
450
YL
TACH SENDER (+)
924
GN
XMSN SOL NO 4 OR 5 RETURN
483
BR
BRAKE FLUID LEVEL
925
YL
XMSN SOL NO 5 OR 4 RETURN
926
BU
XMSN SOL NO 6 RETURN
Off Machine Switch Specifications
Part No. Function Actuate Deactuate Contact Position
6T2665 Coolant Temperature
107.2 ± 2.8°C
(225 ± 5°F)
93°C MIN
(196°F MIN)
Normally
Closed
8T8640 Transmission Pressure
1206 kPa MAX
(175 psi MAX)
700 ± 103 kPa
(100 ± 15 psi)
Contact 1 - 3 (N.C.)
Contact 1 - 2 (N.O.)
9D6888 Refrigerant Pressure
234 kPa MAX
(34 psi MAX)
152 kPa MIN
(22 psi MIN)
Normally
Open
9W1520 Engine Coolant Temp (Start Aid)
37.8 ± 2.8°C
(100 ± 5°F)
26.7°C MIN
(80°F MIN)
Normally
Closed
9W4139 Brake Pressure
13780 kPa MAX
(2000 psi MAX)
10335 ± 689 kPa
(1500 ± 99 psi)
Normally
Closed
N.C. Normally Closed.
N.O. Normally Open.
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
SENR5821
May 1993
446B Backhoe Loader
Electrical System
5BL1-UP
©
1993 Caterpillar
All Rights Reserved
Printed in U.S.A.
1
E
1
E
1
E
1
E
1
1
A
3
4
5
6
8
9
10
11
12
14
15
13
16
B
C
D
1
2
17
18
19
20
21
22
23
24
25
26
27
7
F
A
3
4
5
6
8
9
10
11
12
14
15
13
16
B
C
D
1
2
17
18
19
20
21
22
23
24
25
26
27
7
F
Machine Harness Connector And Component Locations
GND
7
1
1
1
1
2
2
1
1
2
3
1
4
1
2
3
4
6
7
9
10
5
8
6
2
3
6
4
3
2
1
C
B
A
3
2
2
1
2
1
5
4
1
2
3
5
3
1
2
12
3
6
1
11
10
9
8
7
6
5
4
3
5
2
1
1
2
12
11
10
9
4
2
1
4
5
1
6
2
2
1
8
7
6
5
4
3
2
1
12
11
2
10
9
8
1
7
6
5
4
3
2
1
7
2
C
B
A
1
1
2
2
1
10
8
9
1
2
11
12
116-BR-16
ATTACHMENT REAR FLOOD LAMP SW
REAR FLOOD
LAMP SW
3E-7268
116-BR-12
116-BR-16
630-GY-16
608-GN-16
6
4
3
1
5
2
GND
B+
P
T
MOTOR
L
H
BR-16
GY-16
BK-16
OR-16
GN-16
5
3
6
2
4
16 GA
417-GY
415-GN
405-GY
415-GN
B
406-PU
C-9
L45
D-9
L45
L27
415-GN
E-4
483-BR
L45
L17
119-PK
L17
L14
L14L14
415-GN
L28
L14
L28
L28L28
L29
L29
L29
L29
L45
568-GN
L28
405-GY
L28
109-OR-10
568-GN
109-OR-10
406-PU
109-OR-10
568-GN
417-GY
109-OR-10
L26
109-OR-10
568-GN
109-OR-10
483-BR
L3
L3
L3
D
L3
D
D
L3
L2
L3
TO
PLATFORM
TO
PLATFORM
TO
PLATFORM
T
T
W/ATCH HARNESS AS. T CONNECT
HARNESS AS. B AND BEACON
9X-8079 AS SHOWN
603-PK
MAGNETIC
BEACON
9X-8079
B
200-BK-16
603-PK-16
RD
BK
T
V
F
200-BK
417-GY
113-OR
V
D
200-BK-16
200-BK
200-BK-16
200-BK
200-BK
200-BK-10
200-BK
126-PK
307-OR
306-GN
121-YL
126-PK-16
E
E
200-BK
200-BK
417-GY
E
RE
R
R
R
200-BK
R
BK-16
483-BR RD-16
R
D
L11
200-BK
G
D
EE
DD
TO
ENGINE
BK-6
CCCC
BK-00
TO
FRAME
WITH ATTACH BEACON REPLACE 10A FUSE WITH
15A FUSE
FUSES 10A-9W-1442 15A-9W-1441 20A-9W-1446
NORMALLY CLOSED WHEN BRAKE IS DEPRESSED
NORMALLY CLOSED AT PROPER REFRIGERANT CHARGE
A-2
A-3
A-3
A-2
A-2
B-6
B-1
F-8
F-8
B-4
C-3
C-3
01
01
00
00
01
01
01
00
V
T
S
ATCH
ATCH
ATCH
ATCH
V
V
PRIMARY STEER LAMP
8L-9801
417-GY
DD
447-PK
BRAKE SW
9W-4139
L25
XSMN PRESS
REVERSE SW
8T-8640
483-BR
200-BK
417-GY
BK
F
419-YL
BU-16
RD-16
447-PK
BK-6
126-PK-16
200-BK-16
121-YL
321-BR
483-BR
754-BU-16
923-GY-16
921-WH-16
922-BR-16
752-YL-16
751-GN-16
926-BU
901-WH
755-OR-16
924-GN-16
925-YL-16
900-PU-16
SHIFT
CONTROL
101-1585
4
5
5
6
4
3
1
2
5
2
4
200-BK-16
Y
Y
BK-14
B
B
B
B
B
B
B
G
A
SEND
H
H
B
B
G
G
103-YL-16
109-OR-10
T
109-OR-16
H
H
H
603-PK-16
L39
H
H
307-OR
SOCKET AS.
9R-7941
200-BK
200-BK
N/O
N/C
1
3
L25
REAR WIPER
SW
7T-9303
B
H
L
P
W
B
D
D
E
D
311-WH
1
D
D
D
D
ALT
P
Z
4D-6565
L27
L27
L31
L31
L38
L38
L37L44
L44L44
RD
BU
L42 L42
L42
L43
L43
PRIMARY
STEER SW
9X-3395
L43
L34
L34
L30L30
L7
L7
L11
L11L11
L11
DE
L18
L25
L12
L12
L22
F-1
L7
L7
L17
L23
L30
L30
L30
901-WH
L34
L34
ATCH
L35
L35
L35
L35
E-7
L36
L36
L36
L36
L36
L37
L37
L37
L37
L38
L38
L39
L39
L27
01
L26
L26
926-BU
L L
L
L
L
L
L
L
D
109-OR-10
B
B
M
G G
B
B
G
D
F-9
D-1
C-4
R
B-6
H
H
H
H
H
H
H
H
H
E-4
B-7
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
ATCH
H
H
P
ATCH
H
H
H
H
H
H
H
H
H
H
ATCH
H
121-YL
112-PU-10
ATCH
H
H H
ATCH
H
H
H
H
H
200-BK
200-BK
ATCH
610-OR-16
441-OR
200-BK
200-BK
443-YL
200-BK
200-BK
200-BK
200-BK
441-OR
443-YL
447-PK
123-WH
NOTE
LOC
D+
R
607-PK-16
B+
123-WH
123-WH
123-WH
123-WH
01
00
02
9R-7939
7T-3550
9R-8625
9R-8624
9R-9555
9R-8623
103-5683
100-4971
100-4969
9R-8619
8R-6892
01
00
EE
DD
L
123-WH
200-BK
L18
START OUT
START IN
BR
03
02
PK
02
200-BK
200-BK
GN
8
200-BK
7
310-PU
604-OR
01
L25
6
YL
GN
+ BATTERY
BASE
LENS
GROUND
3
2
4
1
03
OR
BK
5
751-GN
752-YL
922-BR
921-WH
923-GY
754-BU
900-PU
925-YL
924-GN
755-OR
901-WH
926-BU
121-YL
L39
766-GN
H
K
321-BR
H
SOL 3 (-)
SOL 2 (-)
M
N
P
N
N
N
120-YL-12
310-PU
YL
B
BB
121-YL
H
BU
L39
L39
L41
L39
522-WH
520-WH-12
1
2
552-WH
322-GY
143-BR
405-GY
113-OR
GN
614-PU
307-OR
200-BK
200-BK
200-BK
161-PK
119-PK
H
200-BK
200-BK
304-WH-10
START
RELAY
7X-1379
521-YL
522-WH
200-BK-12
120-YL-12
200-BK-12
614-PU
614-PU
634-WH-16
L6
L2
H
502-OR
500-BR
123-WH
762-YL
AA
02
B
118-GY
B
501-GN
200-BK
200-BK-12
L25
200-BK-12
605-YL
606-GY
405-GY
113-OR
536-WH
605-YL
606-GY
406-PU
419-YL
128-PK
605-YL
606-GY
639-WH
640-GN
SOL 5 (-)
307-OR
6
WH
SOL 1 (+)
SOL 1 (-)
SOL 6 (-)
3
RESISTOR
7T-3828
2
515-GY-12
5
PU
OR
1
4
516-GN-12
2
3
SOL 4 (+)
L25
BK-16
406-PU
SOL 4 (-)
GN-16
322-GY
WH
RD-16
WH-16
4
6
1
BR
200-BK
GY
322-GY
200-BK
200-BK
620-WH
200-BK
BU
502-OR
500-BR
200-BK
119-PK
200-BK
502-OR
501-GN
500-BR
504-YL
505-BU
639-WH
119-PK
640-GN
119-PK
604-OR
118-GY
536-WH
L41
200-BK
605-YL
128-PK
322-GY
102-BU
503-BR
YL
L6
200-BK
109-OR-12
M
419-YL
N
LAMP CHECK
RELAY
7X-1379
419-YL
L2
568-GN
113-OR
552-WH
200-BK-12
K
405-GY
L1
GN
H
H
H
H
87
87a
87a
87
30
86
85
406-PU
122-BU-12
515-GY-12
118-GY
419-YL
200-BK-12
L32
113-OR
517-BU-12
143-BR
606-GY
H
G
E
D
9R-6859
MOTOR
161-PK
HEATER
BLOWER SW
6P-3236
122-BU-12
200-BK-12
113-OR
SOL 5 (+)
417-GY
405-GY
113-OR
143-BR
536-WH
SOL 6 (+)
5
321-BR
128-PK
322-GY
200-BK-10
200-BK
126-PK-16
109-OR-10
109-OR-10
SOL 3 (+)
603-PK
608-GN-16
303-BR
200-BK
00
450-YL
103-YL-10
306-GN
SOL 2 (+)
200-BK-16
NEUTRAL SW
BKUP IN
E
L
D
4F
L41
B
L17
308-YL
L32
308-YL
308-YL
M
105-BR-16
415-GN
ACC RELAY
7X-1379
200-BK
B
109-OR-10
306-GN
307-OR
MAIN
RELAY
7X-1379
K
L16
308-YL
L17
L25
H
308-YL-16
K
310-PU-16
K
3F
310-PU-16
309-GY
614-PU
L40
L44
L16
308-YL
L12
L12
L23
606-GY
200-BK-16
610-OR
620-WH
109-OR-10
161-PK-16
143-BR
200-BK
200-BK
308-YL
H
102-BU
102-BU-16
L23
304-WH-10
109-OR-10
109-OR-10
109-OR-10
109-OR-10
E
H
506-PU
620-WH-16
610-OR-16
607-PK-16
603-PK
608-GN-16
630-GY-16
441-OR
443-YL
447-PK
B
450-YL
01
8Y-7236
310-PU-16
309-GY
1V-1151
200-BK-16
536-WH-16
161-PK-16
307-OR
01
415-GN
308-YL
306-GN
121-YL
128-PK
113-OR
143-BR
126-PK
618-YL
143-BR
415-GN
L22
A
L22
L19
103-YL-16
9R-7958
116-BR-16
Z
BB
L# CIRCUIT GROUPING
DESIGNATION
116-BR-16
H
200-BK-12
102-BU-16
L19
102-BU-16
9R-8722
157-YL
200-BK
L19
2F
109-OR-16
109-OR-16
109-OR-10
304-WH-10
L18
103-YL-10
2
FRONT FLOOD
LAMP SW
3E-7270
2 1
1F
620-WH-16157-YL
H
H
H
TO
PLATFORM
L40
N
2
L1
630-GY-16
608-GN-16
12
Y
2 1
9R-6501
6Y-2167
634-WH-16
610-OR-16
367-BU
L32
K
H
102-BU
H
1R
L40
L42
2R
119-PK
103-YL-16
H
K
K
L40
614-PU
3R
H
113-OR
L32
L18
H
H
E
COOLANT
TEMP GAGE
3E-8535
VOLTMETER
3E-8533
E
SERVICE
METER
6T-7337
TACHOMETER
3E-3507
K
X
KEY START SW
3E-7341
450-YL
200-BK
A
303-BR
A
4R
116-BR-12
614-PU
128-PK
12V
OUTPUTS
614-PU
112-PU-10
200-BK
N
123-WH
TO
GND
157-YL
614-PU
K
E
START
AID SW
3E-7272
L18
614-PU
H
614-PU
A
E
H
M
SOL
RET
109-OR-10
128-PK
K
367-BU
103-YL-10
E
B
B
200-BK
A/C
RELAY
7X-1379
109-OR-10
109-OR-10
P
B
U
REAR HORN
YL-16
P
S
T6
G
E
L
LE
E
N
30
30
87
E
FLOOD
LAMP
9X-6853
D
P
102-BU
200-BK
200-BK 200-BK
102-BU
TO RADIO
119-PK
536-WH-16
161-PK-16
87
87a
87a
85
85
54
9R-9607
M
P
S
CONNECT HARNESS AS. S TO HARNESS
AS. B AND BEACON 9R-8250 AS SHOWN
3
321-BR
603-PK-16
603-PK
E
21
E G
B
SOLENOID
GEAR
9R-6500
FIXED
BEACON
9R-8250
603-PK-16
200-BK
A
126-PK-16
BKUP OUT
B
S
S
200-BK
200-BK
7P-6682
200-BK
AA
200-BK
200-BK
01
P
CC
NOTE D:
E
E
L16
L40
N
L41
L
L
L25
L16
E
L25
L
M
A
E
D
417-GY
113-OR
L26
L31
L38
K
A
L7
L7
B
608-GN
923-GY-16
754-BU-16
922-BR-16
754-BU-16
752-YL-16
A
923-GY-16
921-WH-16
752-YL-16
OR-16
BR-16
751-GN-16
922-BR-16
925-YL-16
K
751-GN-16
900-PU-16
921-WH-16
924-GN-16
K
900-PU-16
K
755-OR-16
K
L35
925-YL-16
926-BU
755-OR-16
901-WH
924-GN-16
86
86
NO. 2 SOL
(FORWARD)
3E-6268
614-PU
614-PU
BAT
406-PU
762-YL
NOTE B:
630-GY
THIS SCHEMATIC IS FOR THE 446B BACKHOE
(105-3504 CHG 00)
CABLE AS.
630-GY-16
447-PK
603-PK
6
3
1
419-YL
5
419-YL
322-GY
200-BK
200-BK
OR-16
610-OR
417-GY
200-BK
200-BK
143-BR
2
WIRE AS.
HARNESS AS.
LOCPART NO.IDENT
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
NOTE A:
COMPONENTS ARE SHOWN INSTALLED ON A FULLY
OPERABLE MACHINE WITH THE KEY AND ENGINE OFF,
AND XMSN SHIFTER IN NEUTRAL
UNLESS OTHERWISE SPECIFIED: ALL WIRE IS 18 GAGE
3 2
A
B
C
3 2
F
E
D
6 5 4
6 5 4
9 8 7
C
B
A
9 8
F
E
D
123-WH
H
MOTOR
TO
PLATFORM
123-WH
200-BK
200-BK
FLOOD
LAMP
9X-6853
STOP/
TAIL
LAMP
3E-7398
T
S
200-BK
200-BK
200-BK-16
200-BK
B
605-YL
610-OR
620-WH
367-BU
639-WH
200-BK
617-BR
617-BR
639-WH
200-BK-16
610-OR
113-OR
128-PK
4
E
9R-9554
FAN AS.
5D-2855
119-PK
RD
OR-14
RD-14
308-YL-16
116-BR-12
161-PK
GY-16
3
GN-16
605-YL
620-WH
608-GN
200-BK
1
1
119-PK
200-BK-16
S
S
TO
ENGINE
K
K
K
K
309-GY
9D-8047
766-GN
H
3E-9093
161-PK
128-PK
322-GY
640-GN
639-WH
605-YL
606-GY
122-BU-12
419-YL
HH
NO. 3 SOL
(FOURTH GEAR)
3E-6268
126-PK
405-GY
450-YL
BK-14
BLOWER
MOTOR
3E-7501
Z
415-GN
2
200-BK
OPERATOR STATION
OPERATOR STATION
REAR WIPER
MOTOR GP
3E-7566
NO. 4 SOL
(FIRST GEAR)
3E-6268
K
504-YL
505-BU
503-BR
119-PK
C
B
E
BK-16
L
H
MOTOR
L7
9R-9606
TO
ENGINE
A
450-YL
A
BACKUP
ALARM
102-9236
606-GY
BK
BK
536-WH
200-BK
200-BK
610-OR-16
605-YL
417-GY
NOTE
H
307-OR
T
S
STOP/
TAIL
LAMP
3E-7398
200-BK
FLOOD
LAMP
9X-6853
640-GN
618-YL
200-BK
200-BK
200-BK
310-PU-16
441-OR
630-GY
308-YL
194-GN-10
443-YL
603-PK
200-BK-16
200-BK
630-GY
FLOOD
LAMP
9X-6853
103-YL-10
PARK
BRAKE SW
6T-5925
BK-16
D
200-BK
608-GN
D
200-BK
200-BK-16
200-BK-12
200-BK
161-PK-16
STOP LAMPS
HAZARD LAMPS
121-YL
H
M
P
308-YL
BK
614-PU
102-BU-16
121-YL
419-YL
L6
536-WH-16
H
H
H
H
H
607-PK-16
NOTE C:
30
86
85
H
H
H
H
200-BK
614-PU
116-BR-12
H
200-BK
H
H
H
CONV
TEMP
GAGE
3E-8534
200-BK
H
367-BU
119-PK
200-BK
K
10A
XSMN CONTROL
H
200-BK-16
M
H
CHG
FUSE
HOLDER
9W-2035
NOTE C
112-PU-10
10A
200-BK
FLOOD
LAMP
9X-6853
447-PK
- +
SIG
IGN
SEND
GRD
OPERATOR STATION
OPERATOR STATION
IGN
SEND
GRD
IGN
SEND
GRD
IGN
GRD
RESISTOR
8C-4110
607-PK-16
15A
DIODE
8C-5444
15A
LAMP
8M-6176
REAR FLOOD
LAMP SW
3E-7270
BEACON SW
3E-7270
ACC
A
ST
ON
OFF
B
S
LAMP
8M-6176
LAMP
8M-6176
443-YL
LAMP
8M-6176
FRONT DRIVE
321-BR
49A
BACKUP ALARM/BEACON
OUT (LAMP)
+ BATTERY
GROUND
31
49
30
86
FLASHER
7T-4848
126-PK
157-YL
MONITOR LAMPS
122-BU-12
618-YL
617-BR
TRANSMISSION
NEUTRALIZER SW
8T-8756
LEFT TURN
IND LAMP
8M-6176
B-7
A-4
PANEL
LAMP
8L-9801
620-WH
FLOOD
LAMP
9X-6853
620-WH
200-BK
E
TURN/HAZARD SW
9X-9547
200-BK-16
610-OR
FLOOD
LAMP
9X-6853
TURN
LAMP
3E-7500
610-OR
200-BK
605-YL
85
87a
87
30
200-BK
RD-00
RD-00
BK-00
BK-00
109-OR-10
606-GY
109-OR-10
109-OR-10
16 GA
16 GA
BATTERY
3T-5760
BATTERY
3T-5760
NEG POS NEGPOS
86
501-GN
119-PK
503-BR
505-BU
504-YL
119-PK
102-BU
113-OR
04
194-GN-10
128-PK
200-BK
C
KEY
R
105-BR-16
RIGHT TAIL LAMP
LEFT TAIL LAMP
HEATER
CAB
RELAY
7X-1379
634-WH-16
OPERATOR STATION
1
3
CC
2
COM
N/C
N/O
417-GY
F
483-BR
E
E
F
F
P
ENGINE OIL
PRESS LAMP
8M-6176
RIGHT TURN
IND LAMP
8M-6176
COOLANT
TEMP LAMP
8M-6176
PARK BRAKE
LAMP
8M-6176
NO. 5 SOL
(SECOND GEAR)
3E-6268
16 GA
2
16 GA
9D-2868
119-PK
113-OR
85
441-OR
LAMP
8M-6176
415-GY
FRONT
WIPER SW
7T-9303
BUCKET
POSITIONER
SOLENOID
3E-8620
M
617-BR
307-OR
306-GN
126-PK
447-PK
121-YL
128-PK
200-BK-16
FUEL
SENDER
6T-0454
B-4
FLOOD
LAMP
9X-6853
TURN
LAMP
3E-7500
87a
87
1
122-BU-12
506-PU
608-GN-16
618-YL
617-BR
630-GY-16
620-WH-16
610-OR-16
B-4
OR-14
128-PK
603-PK
113-OR
X
L12
200-BK-16
10A
304-WH-10
610-OR
620-WH
606-GY
605-YL
640-GN
639-WH
122-BU-12
606-GY
603-PK
620-WH
610-OR
617-BR
608-GN
639-WH
630-GY
605-YL
200-BK-16
200-BK
200-BK
200-BK
605-YL
640-GN
639-WH
608-GN-16
618-YL
617-BR
620-WH-16
630-GY-16
10A
109-OR-10
16 GA
16 GA
NO. 6 SOL
(THIRD GEAR)
3E-6268
2
1
7
20A
D
B
766-LT GN
552-WH
322-GY
483-BR
9D-2868
Z
766-GN
126-PK
G
9D-8047
200-BK
306-GN
307-OR
C
15A
126-PK
BASE
LENS
447-PK
8
200-BK
FRONT DRIVE
LAMP
8M-6176
766-LT GN
ENGINE
OIL SW
7W-1238
161-PK-16
603-PK-16
610-OR-16
603-PK
FIXED
BEACON
9R-8250
321-BR
109-OR-10
109-OR-10
552-WH
2
1
406-PU
143-BR
BRAKE SW
6T-5925
NOTE B
L30
L30
TO PLATFORM
123-WH
128-PK
322-GY
521-YL
FORWARD
HORN SW
3T-2357
10A
10A
10A
10A
10A
128-PK
113-OR
123-WH
121-YL
116-BR-12
118-GY
119-PK
FRONT FLOOD
BUCKETPOS/HORN
FRONT WIPER
REAR WIPER
REAR FLOOD
GAGES
RUNNING LAMP
BREAKER
3T-2662
15A
20A
121-YL
308-YL
506-PU
503-BR
118-GY
505-BU
504-YL
500-BR
501-GN
502-OR
BK
BK
311-WH
128-PK
762-YL
118-GY
BB
200-BK
568-GN
310-PU
568-GN
419-YL
309-GY
311-WH
BK
BK
B
B
H
L
W
P
310-PU
311-WH
ENGINE
SHUTDOWN
SOL
8C-3662
326-PU
START AID
SOL
3T-9493
P
200-BK-10
10A
F
301-BU-10
505-BU
504-YL
503-BR
OPERATOR STATION
MOTOR
BK-16
RD-16
K
102-BU-16
2
614-PU
L
A-8
102-BU-16
102-BU-16
102-BU-16
H
6
B-7
450-YL
TO
ENGINE
3
4
5
2
1
FRONT WIPER
MOTOR GP
3E-7394
606-GY
568-GN
552-WH
301-BU-10
113-OR
483-BR
568-GN
DIODE AS.
2V-9473
DIODE AS.
2V-9473
BRAKE LAMP
8L-9801
603-PK
102-BU-16
BLOWER
3E-7501
3
3
4
5
2
STARTER
3E-5382
BLOWER SW
6P-3236
RESISTOR
7T-3828
517-BU-12
516-GN-12
515-GY-12
120-YL-12
520-WH-12
109-OR-10
NOTE D
304-WH-10
FORWARD
HORN
7T-0635
200-BK
441-OR
102-BU
118-GY
S
G
1
RUNNING
LAMP SW
3E-7268
DOME
LAMP
4M-3601
200-BK
BK
WH
200-BK
10A
515-GY-12
FUSE HOLDER
4K-5122
124-GN-12
C
B
A
MOTOR
E
BK-14
900-PU
E
925-YL
924-GN
755-OR
751-GN
752-YL
922-BR
921-WH
OPERATOR STATION
X
521-YL
521-YL
521-YL
522-WH
513-OR
REFRIGERANT SW
9D-6888
NOTE A
513-OR
923-GY
311-WH
109-OR-10
E
419-YL
311-WH
405-GY
326-PU
443-YL
441-OR
450-YL
309-GY
406-PU
405-GY
326-PU
568-GN
326-PU
326-PU
406-PU
AIR
CONDITIONER
CLUTCH
SOL
7T-7825
405-GY
K
RD-00
326-PU
443-YL
E
START AID
SW
9W-1520
L16
ACTION
ALARM
3E-6330
BB
TO
FRAME
AA
L
118-GY
NO. 1 SOL
(REVERSE)
3E-6268
CONVERTER
SENDER
4W-9972
200-BK-10
568-GN
FRONT DRIVE
SW
3E-7270
200-BK
200-BK
113-OR
AA
N
P
P
P
16 GA
16 GA
16 GA
16 GA
ALTERNATOR
55A 3E-7295 STD
90A 9X-0341 ATCH
FRONT DRIVE
SOLENOID
6T-6885
552-WH
754-BU
TO
PLATFORM
START
GND
STOP
RD-16
RD-16
E
301-BU-10
2
5
3
1
D
113-OR
THERMOSTAT SW
3E-5465
OR-14
10A FUSE 3K-8782
20A FUSE 8M-0546
20A
124-GN-12
522-WH
200-BK-16
T
6
L
552-WH
4
200-BK406-PU
H
H
COOLANT SW
6T-2665
COOLANT
SENDER
4W-9972
441-OR
FUEL GAGE
3E-8532
RETURN
TO DIG SW
9G-2795
M
A
2
H
1
200-BK
450-YL
5
~T
T
4
M
D
200-BK-10
K
443-YL
200-BK
D
EE
16 GA
D
309-GY
450-YL
MTR
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.
MONITOR CIRCUIT.
PANEL LAMP CIRCUIT.
WIPER/WASHER CIRCUIT.
HEATER AND AIR CONDITIONER CIRCUIT.
GROUND CIRCUIT.
ENGINE SHUTDOWN CIRCUIT.
TURN SIGNAL CIRCUIT.
START AID CIRCUIT.
ALL DASHED LINES ARE ATTACHMENTS.
+ -
T
T