Connector Location Connectors
Machine Location
8 15
26
22
24 27
19
1
11
2 5
12
20
E-3
A
*
W - 9U1419 Transmission Cont
D-7
1
37 Contacts
1
A - 4E8279 B - 4E9196
C-6
4
25 Contacts
D
C - 4E9682 J - 9U2275
A-11
6
1
B - 4E9196 W - 9U1419
D-8
1
Q - 4E8277 Std W - 9U1419
E-6
1
Q - 9U3907 Atch W - 9U1419
21
C
6
A
9
1
16
4
18
13 D
7
2
23
1 3
10
3
E
B
6
B - 4E9196 U - 4E6635
A-7
E - 4E6638 U - 4E6635
A-3
E - 4E6638 Y - 4E6644
B-2
7
E - 4E6638 Y - 4E6644
D-2
8
KK - 3E8843 BBB - 3E7325
E-5
F-11
*
A - 4E8279 Front Wiper Motor
C-3
LL - 7I3312 RR - 7I3311
F-6
*
A - 4E8279 Voltage Converter
C-6
D
J - 9U2275 Diagnostic Connector
A-10
*
D - 4E8229 Rear Wiper
E-5
*
RR - 7I3311 Payload Monitor Cont
D-9
*
J - 9U2275 Shutdown Control
A-10
14 Contacts
W - 9U1419 TT - 8E6402
F-9
*
LL - 7I3312 Payload Display
A-2
1
A - 4E8279 B - 4E9196
D-6
E
A - 4E8279 D - 4E8229
D-5
E
A - 4E8279 D - 4E8229
D-5
1
B - 4E9196 RR - 713311
A-8
E
A - 4E8279 S - 9U0785
C-4
8
H - 4E9I04 ZZ-4E9103
F-2
B - 4E9196 C - 4E9682
C-10
E
A - 4E8279 Hydraulic Hand Sw
A-3
D
B - 4E9196 J - 9U2275
B-9
A
A - 4E8279 Service Plug (CMS)
C-3
1
B - 4E9196 K - 4E6641
E-7
*
K - 4E6641 Park Brake Sw
F-7
1
B - 4E9196 U - 4E6635
A-7
*
L - 4E6642 Fuel Sensor
F-7
4
E - 4E6638 U - 4E6635
A-2
1
W - 9U1419 Service Plug (Trans)
E-8
E
A - 4E8279 G - 4E7243
A-5
*
Q - 4E8277 Steer Lock Sw
F-4
E
A - 4E8279 S - 9U0785
C-4
5
B - 4E9196 F - 4E6636
C-11
*
D - 4E8229 Front Wiper Sw
D-4
*
D - 4E8229 Radio
F-5
*
Q - 4E8277 Std Shifter Control
F-4
*
Q - 9U3907 Atch Shifter Control
F-10
*
LL -713312 Payload Display
A-2
2
3
12 Contacts 9
8
C
5 6
27 1
19
D
21
20
12 24
2 5
1
22
B
A
7
8
17 6
18
23
25
10
2
3
11
4 7
16
14
13
26
E
15 4
3
8 Contacts
C48646P1
MACHINE HARNESS CONNECTOR AND COMPONENT LOCATIONS
6 Contacts
4 Contacts
SENR5738 February 1993
Schematic Location C-3
7
14
Harness And/Or Components A - 4E8279 Z - 4E8247
20 Contacts
25
Machine Location
Connectors
A - 4E8279 CMS Cont
17 5
Schematic Location
* 40 Contacts
4
Harness And/Or Components
Electrical Schematic Symbols And Definitions
T
Temperature Symbol
Pressure Symbol
Flow Symbol
Level Symbol
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.
988F Wheel Loader Electrical System
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.
8YG1-UP 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.
Machine locations are repeated for connectors located close together. * = Connector is located at the component. A = Connectors located in dash area. D = Connectors located in relay panel area. E = Connectors located in right side service compartment.
Printed in U.S.A.
© 1993 Caterpillar All Rights Reserved
Component Alarm - Action (CMS)
Schematic Location F-3
Component Location Machine Location A
Component Sensor - Lift Cylinder Pressure (PMS)
Schematic Location D-1
Machine Location 16
Resistor, Sender and Solenoid Specifications
Part No.
Component Description
Overall 3.0 ± .15 Tap 1.0±.05
Resistor - Blower Speed
9X-4383
Resistance (Ohms)¹
Alarm - Backup
D-12
1
Sensor - Lift Position (PMS)
D-1
17
3E-7842
Resistor - Starter/Diagnostic Conn
150.0 ± 7.5
Alternator
D-11
2
Sensor - Power Train Temp (CMS)
E-11
18
8T-8813
Solenoid - A/C Clutch
14.4 ± 0.6
Batteries
B-12
3
Sensor - Torque Converter Speed
D-9
18
Batteries
F-12
4
Sensor - Transmission Speed
D-9
13
6I-2090
Solenoid - Engine Shutdown
3.7 ± 0.4
Breaker - Alternator (80 Amp)
B-11
D
Shifter - Transmission
F-10
C
3E-6333
Solenoid - Start Aid
Breaker - Circuit (Blower Motor) 15 Amp
A-6
E
Solenoid - A/C Clutch
B-11
2
Breaker - Circuit (Seat) 15 Amp
A-6
E
Solenoid - Bucket Float
B-4
B
Breaker - Engine Shutdown (15 Amp)
A-11
D
Solenoid - Bucket Kickout
B-4
B
Breaker - Key Switch (10 Amp)
B-10
D
Solenoid - Engine Shutdown
E-11
19
Breaker - Main Power (80 Amp)
B-10
D
Solenoid - First Gear (Clutch 8)
E-8
20
Breaker - Running Lamps (10 Amp)
B-10
D
Solenoid - Forward (Clutch 2)
F-9
20
Control - Engine Shutdown
A-10
D
Solenoid - Fourth Gear (Clutch 3)
F-8
20
Control - Hydraulic Hand (VCTC)
A-3
B
Solenoid - Lift Kickout
B-4
B
Control - Lever Steer Shifter
F-4
5
Solenoid - Lockup Clutch
D-9
20
Control - Payload Monitor ECM (PMS)
D-9
6
Solenoid - Reverse (Clutch 1)
F-9
20
Control - Transmission
D-7
6
Solenoid - Second Gear (Clutch 5)
E-8
20
Converter - Voltage
C-6
E
Solenoid - Start Aid
C-10
21
Display - Payload Measurement System (PMS)
B-3
A
Solenoid - Third Gear (Clutch 4)
F-B
20
Fuse Holder
A-6
E
Solenoid - VCTC Valve
D-10
18
Fuses (10 Amp)
A-6
E
Switch - Battery Disconnect
D-11
2
Fuses (15 Amp)
A-5
E
Switch - Blower
E-4
9
Horn - Forward
B-2
7
Switch - Brake Pressure
F-8
22
Horn - Forward
E-2
8
Switch - Bucket Positioner
B-1
23
Lamp - Action (CMS)
F-3
A
Switch - CMS Brightness Adjustment
C-4
B
Lamp - VCTC Indicator
D-3
A
Switch - Coolant Flow (CMS)
F-11
24
Meter - Service
E-4
A
Switch - Flood Lamp
C-4
B
Monitor - Computerized System (CMS)
E-3
A
Switch - Floor Blower
D-4
B
Motor - Blower
E-4
9
Switch - Forward Horn
D-3
C
Motor - Floor Heater Blower
B-2
B
Switch - Front Wiper
D-4
9
Motor - Front Washer
A-7
10
Switch - Key Start
C-4
B
Motor - Front Wiper
C-3
A
Switch - Lift Kickout
B-1
25
Motor - Rear Washer
A-7
10
Switch - Neutralizer Limit
F-3
C
Motor - Rear Wiper
E-6
9
Switch - Neutralizer Override
B-4
B
D-11
11
Switch - Neutralizer pressure
F-8
22
F-5
9
Switch - Park Brake
F-7
22
Receptacle - Auxiliary Start
A-12
2
Switch - Parking Brake Pressure
F-8
22
Relay - Flood Lamp
A-5
E
Switch - Quickshift
C-3
B
Relay - Main Power
B-10
D
Switch - Rear Wiper
E-4
9
Relay - Start
A-10
D
Switch - Refrigerant (A/C)
B-11
26
Resistor - Blower Speed
E-5
9
Switch - Reweigh (PMS)
A-3
B
Motor - Starter Radio
Resistor - Starter Diagnostic
D-11
11
Switch - Running Lamp
D-4
B
Resistor - System Voltage (CMS)
A-9
D
Switch - Start Aid
C-4
B
Seat - Air Suspension
D-5
C
Switch - Steer Lever Lock
F-4
B
Sensor - Engine Coolant (CMS)
E-11
12
Switch - Stop Lamp
F-8
22
Sensor - Engine Oil Pressure (CMS)
E-11
11
Switch - Store (PMS)
A-3
B
Sensor - Engine Speed (CMS)
F-10
13
Switch - Thermostat
E-5
9
Sensor - Fuel Level
F-8
14
Switch - Transmission Filter (CMS)
F-11
27
Sensor - Hydraulic Oil Temperature
A-8
15
Switch - Turn Signal
D-6
C
Machine locations are repeated for components located close together. A = Components located in dash area. B = Components located in right console area. C = Components located in operator’s compartment. D = Components located in relay panel. E = Components located in right side service compartment.
6.0
Solenoids - Transmission Solenoid - VCTC Valve
3E-3748 4V-1222
8.5 41.5 ± 4.2
¹ At room temperature unless otherwise noted.
Part No.
Actuate
Deactuate
Contact Position
Brake Pressure
8270 kPa MAX (1199 psi MAX)
6890 ± 345 kPa (1000 ± 50 psi)
A-B, Normally Open A-C, Normally Closed
4E-4456
Neutralizer Pressure
790 ± 140 kPa (114 ± 20 psi)
690 ± 105 kPa (100 ± 15 psi)
Normally Closed
8N-1693
Coolant Temperature (St Aid)
38 ± 3°C (100 ± 5°F)
27°C MIN (80°F MIN)
Normally Closed
3E-6452
9X-7781
Function
Off Machine Switch Specification
210 ± 70 kPa (30 ± 10 psi)
Trans Filter Pressure
Module Identifiers (MID) MID No. 26 27
FMI No.
CID No.
Computerized Monitoring System (CMS) Electronic Transmission Control
Failure Mode Identifiers (FMI) List Failure Description
0
Data valid but above normal operational range.
1
Data valid but below normal operational range.
2
Data erratic, intermittent, or incorrect.
3
Voltage above normal or shorted high.
4
Voltage below normal or shorted low.
5
Current below normal or open circuit.
6
Current above normal or grounded circuit.
7
Mechanical system not responding properly.
8
Abnormal frequency, pulse width, or period.
9
Abnormal update.
10
Abnormal rate of change.
11
Failure mode not identifiable.
12
Bad device or component.
13
Out of calibration.
Related Electrical Service Manuals Computerized Monitoring System (CMS)
Form Number SENR5247
Payload Measurement System (PMS)
SEHS9307
Electronic Transmission Control
SENR5704
Starting And Charging Systems
SENR2947
Starting Motor (50-MT): Consist No. 3T-8967
Normally Open
Component Identifiers (CID)
Module
Title
-
SENR3860
096 100 110 168 177 248 263 270 271 324 600 601 621 622 623 626 627 628 631 632 633 634 635 636 638 653 668 670 671 672 678 679
Component
Fuel Level Sensor Engine Oil Pressure Sensor Engine Coolant Temperature Sensor Electrical System Voltage Power Train Oil Temperature Sensor Data Link +8V Sensor Supply Harness Code Action Alarm Action Lamp Hydraulic Oil Temperature Sensor Brake Air Pressure Sensor Downshift Switch Upshift Switch Direction Switch Lock Switch Parking Brake Switch Quickshift Switch Clutch 1 Solenoid (Reverse) Clutch 2 Solenoid (Forward) Clutch 3 Solenoid (Speed) Clutch 4 Solenoid (Speed) Clutch 5 Solenoid (Speed) Clutch 6 Solenoid (Speed) Start Relay Transmission Control Shift Handle Left Pedal Sensor Transmission Speed Sensor Torque Converter Speed Sensor VCTC Clutch Solenoid Lockup Clutch Solenoid
Wire Number
Wire Color
101
RD
102
BU
103
YL
105 106 107
Wire Description
Harness And Wire Electrical Schematic Symbols
Wire Number
Wire Color
BAT
500
BR
WIPER - FRONT (PARK)
HD LMP
501
GN
WIPER - FRONT (LO)
AUX CKT
502
OR
WIPER - FRONT (HI)
BR
KEY SW
503
BR
WIPER - REAR (PARK)
WH
AUX CKT
504
YL
WIPER - REAR (LO)
WH
ENG SHUT - DOWN FIRE SUPPR
505
BU
WIPER - REAR (Hi)
109
OR
ALT OUTPUT (+) TERM.
506
PU
WASHER - FRONT
112
PU
MAIN POWER RELAY OUTPUT
507
WH
WASHER - REAR
113
OR
OPR MON PANEL VMIS B+ SWITCHED
508
PU
RADIO SPEAKER - LEFT
114
GN
WARNING HORN (FORWARD)
509
WH
RADIO SPEAKER - LEFT (COMMON)
118
GY
AUX CKT
511
BR
RADIO SPEAKER - RIGHT
124
GN
A/C
512
GN
RADIO SPEAKER - RIGHT (COMMON)
128
PK
AUX CKT
513
OR
A/C COMPRESSOR/REFRIGERANT PRESS. SW
129
BU
AUX CKT
515
GY
BLOWER MOTOR (HI)
138
GN
AUTO LUBE PUMP TO PAYLOAD MON
516
GN
BLOWER MOTOR (MEDIUM)
140
BU
AUX CKT
517
BU
BLOWER MOTOR (LO)
150
OR
EUI (ADEM)
519
PK
THERMOSTAT TO REFRIGERANT PRESS. SW
164
WH
HYDRO CONT TO WTL POWERTRAIN CTRL
520
WH
OPR A/C SW TO THERMOSTAT/FUSE
537
GN
TURN SIGNAL SW TO FLASHER
592
BU
DC/DC CONVERTER POWER OUTPUT
Description Power Circuits
Ground Circuits
Description Accessory Circuits
200
BK
MAIN CHASSIS
201
BK
OPR MON PANEL VMIS CMS
A513
PK
DC/DC CONVERTER MEMORY OUTPUT
202
BK
XMSN CONT
A515
BR
BLOWER MOTOR #2 (HI)
203
BK
CHASSIS DIAGNOSTIC
A517
OR
BLOWER MOTOR #2 (LO)
207
BK
STARTER DIAGNOSTIC
250
BK
PAYLOAD MON - CUSTOMER GROUND
600
BR
DASH LAMP BASIC
251
BK
PAYLOAD MON - SYSTEM GROUND
604
OR
STOP LAMP
270
BK
CMS IDENT CODE 0
605
YL
TURN LAMP - LEFT
271
BK
CMS IDENT CODE 1
606
GY
TURN LAMP RIGHT
272
BK
CMS IDENT CODE 2
607
PK
FLOOD LAMP - FRONT
273
BK
CMS IDENT CODE 3
610
OR
HEAD LAMP BASIC
274
BK
CMS IDENT CODE 4
615
YL
CAB FLOOD LAMP/ROPS
278
BK
XMSN CONT IDENT CODE 2
616
BU
BUCKET FLOOD LAMP/BOOM FLOOD LAMP
279
BK
XMSN CONT IDENT CODE 3
637
GN
LCL LAMP
280
BK
XMSN CONT IDENT CODE 4
644
OR
BRIGHTNESS ADJUST
281
BK
XMSN CONT IDENT CODE 5
290
BK
SERVICE
709
OR
SENSOR POWER SUPPLY
291
BK
CLEAR
710
GN
XMSN SPEED PICKUP SIGNAL
751
GN
XMSN SHIFT SOL NO. 1 OR 3
301
BU
STARTER NO. 1 SOL
752
YL
XMSN SHIFT SOL NO. 2
302
OR
STARTER NO. 1 RESISTOR TO DIAGNOSTIC
754
BU
XMSN SHIFT SOL NO. 3 OR 1
304
WH
755
OR
XMSN SHIFT SOL NO. 4 OR 5
306
GN
761
GY
LIFT KICKOUT SOL SW
307
OR
STARTER RELAY NO. 1 OUTPUT STARTER RELAY COIL TO NEUT START SW OR KEY SW KEY SW TO NEUT START SW OR VMIS SENSOR MODULE
308
YL
310
PU
311
WH
313
GY
314
Basic Machine Circuits
YL
BUCKET POSITIONER SOL SW
WH
WTL XMSN CONT TORQUE LIMIT INPUT
D725
OR
START AID SOL TO TEMP SW
D726
PU
WTL XMSN CONT LOCK-UP CLUTCH PROPORTIONAL SOL WTL XMSN CONT STEERING CONSOLE SW 1
STARTER NO. 2 RESISTOR TO DIAGNOSTIC
D727
YL
WTL XMSN CONT STEERING CONSOLE SW 2
PU
STARTER RELAY NO. 2 OUTPUT
D728
BU
WTL XMSN CONT FORWARD SW TO GND
321
BR
BCKP ALARM LAMP TRAVEL ALARM
D729
GY
WTL XMSN CONT REVERSE SW TO GND
322
GY
WARNING HORN (FORWARD)
D730
GN
WTL XMSN CONT SPEED 1 SW TO GND
326
PU
KEY SW “C” TERM.
D731
WH
WTL XMSN CONT SPEED 2 SW TO GND
327
PK
SHUTDOWN SOL
D732
YL
WTL XMSN CONT SPEED 3 SW TO GND
338
PK
FLOOD LAMP RELAY COIL
D733
BR
WTL XMSN CONT SPEED 4 SW TO GND
D734
PU
WTL XMSN CONT NEUTRAL SW TO GND
Monitoring Circuits 403
GN
D735
PK
410
WH
OPR MON ACTION ALARM
D736
GN
WTL XMSN CONT PARK BRAKE LEVER SW TO GND WTL XMSN CONT LOCKUP ENABLE SW
411
PK
OPR MON ACTION LAMP
D756
YL
CMS PARK BRK - LVR STEER
412
BU
OPR MON COOLANT FLOW
D757
OR
TRANSMISSION NEUTRALIZER SW #2
417
GY
PRIMARY STER SW
D758
PU
QUICKSHIFT SW (N.C.) LEVER STEER
419
YL
OPR MON PARKING BRAKE
D759
WH
QUICKSHIFT SW (N.O.) LEVER STEER
426
BR
OPR MON POWER TRAIN OIL FILTER
818
BR
SERIAL DATA (TRANSMIT)
432
PK
OPR MON BRAKE PRESS. (OIL)
819
GY
SERIAL DATA (RECEIVE)
441
OR
ENG COOLANT TEMP GAGE
820
BU
TRANSMIT KEY
442
GY
HYD SYSTEM TEMP GAGE
863
BU
PAYLOAD MON TRANSMIT LCD OUT
443
YL
POWER TRAIN TEMP GAGE
864
BR
PAYLOAD MON CLOCK LCD OUT
447
PK
FUEL LEVEL GAGE
865
GY
PAYLOAD MON LATCH LCD OUT
450
YL
TACH SENDER (+)
900
PU
XMSN SHIFT SOL NO. 5 OR 4
452
PU
TORQUE CONVERTER
901
WH
XMSN SHIFT SOL NO. 6
464
GY
OPR MON PANEL ENG OIL PRESS. SENSOR
944
OR
CMS COMM +
A401
YL
ELECTRICAL SYSTEM NO.1 VOLTAGE
945
BR
CMS COMM -
B412
YL
WTL PMS LIFT POS SENSOR
975
WH
CST AUTOSHIFT- SOL RETURN
B413
PU
WTL PMS LIFT CYL PRESS. SENSOR
976
OR
RIDE CONT SOL
B414
OR
WTL PMS NORM/CALIBRATE OUT
B415
PK
WTL PMS CLEAR / CHG OUT
B416
WH
WTL PMS REWEIGH SW IN
B417
YL
WTL PMS STORE SW IN
B475
OR
PARK BRAKE SW #2
ALTERNATOR (R)TERM.
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
Typical representation of a Sure-Seal connector. The plugand receptacle contain both pins and sockets.
Pin or Socket Number Wire, Cable, or Harness Assembly Identification
Component Part Number
Single Wire Connector C
A
A 325-PK-14
Pin
AA 1
9X-1123 325-PK-14
Wire Color
Socket
2
Control Circuits
762
START AID SW TO START AID SOL
AA
Lighting Circuits
D721
MAIN POWER RELAY COIL
A
200-BK-14
Circuit Number Identification
Wire Gauge
Electrical Schematic Symbols And Definitions 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.
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. 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.