Model 4700 Maintenance Manual
Section 8. Theory of Operation
All Dual Traction Motor Trucks and Single Traction Motor Trucks <S/N 10677 Item
Connection
Function Description
Theory of Operation
Pinout Matrix
Normal Level
Signal Source
Signal User
37
JCT-3
+V KEY
B+ from Key switch (SW1). Used by the TPA to determine BSOC. If not present, check the Key switch, wiring, and connections.
B+
SW1
TPA
38
JCT-4
+V OUT
B+ from TPA to Seat switch (SW2) and optional Battery Interlock switch (SW30). If not present, check the TPA, wiring, and connections.
B+
TPA
TPA
39
JCT-5
SEAT
Input from the Seat switch (SW2). If not present, check the seat switch, battery interlock switch (SW30), jumper, wiring, and connections.
B+
SW2
TPA
40
JCT-6 thru 10
NOT USED
41
JCT-11
+12V
+12V to the Left Traction Motor (LTM) encoder (EN2). If not present, check the TPA, wiring, and connections.
+12V
TPA
EN2
42
JCT-12
GND
Ground to the Left Traction Motor (LTM) encoder (EN2). If not present, check the TPA, wiring, and connections.
Battery voltage wrt BT1+
TPA
EN2
43
JCT-13
RTM ENCODER CHANNEL A
Channel A from the Right Traction Motor (RTM) encoder (EN1). If not present, check voltage to the encoder, wiring, and connections.
Approx. 5V running; 0V or 10V static
EN1
TPA
44
JCT-14
RTM ENCODER CHANNEL B
Channel B from the Right Traction Motor (RTM) encoder (EN1). If not present, check voltage to the encoder, wiring, and connections.
Approx. 5V running; 0V or 10V static
EN1
TPA
45
JCT-15
GND POT
Ground from the TPA to the Steer pot (P1). If not present, check the TPA, wiring, and connections.
Battery voltage wrt BT1+
TPA
P1
46
JCT-16
+V POT
+12V from the TPA to the Steer pot (P1). If not present, check the TPA, wiring, and connections.
+12V
TPA
P1
47
JCT-17
C POT
Input from the Steer pot (P1) to the TPA. If not present, check the Steer pot (P1), wiring, and connections.
Approx. 1.5V steered left; 5.5V centered; 10V steered right
P1
TPA
48
JCT-18 thru 21
NOT USED
49
JCT-22
LTM ENCODER CHANNEL A
Channel A from the Left Traction Motor (LTM) encoder (EN2). If not present, check voltage to the encoder, wiring, and connections.
Approx. 5V running; 0V or 10V static
EN2
TPA
Publication 1160093, Issued: 20 May 2013
8-17
