TM 5-3895-373-20
2.18.
ELECTRICAL CIRCUIT DIAGNOSTICS.
Perform these diagnostic tests whenever you detect a
problem with an electrical control circuit, or if sent here
from another diagnostic procedure.
These diagnostic procedures cover all electrical circuits
except the lighting system, the screed burner system,
hydraulic valve solenoid circuits, and the DCA circuits.
The location of diagnostic procedures for electrical
controls in these systems are listed in the Table of
Contents.
Refer to the diagnostic index for troubleshooting a
specific control switch or indicator circuit. Each electrical
control circuit is identified by the related switch or
indicator located on one of the three paving machine
control panels.
NOTE
When checking live circuit voltage, all
references to 12 vdc are nominal.
The actual voltage measured should
be equal to the voltage at the 12 vdc
terminal of the voltage transformer.
NOTE
When a fault is isolated to a specific
component, the paragraph number of
the repair task for replacement of the
component is cited in the diagnostic
flow chart. If the repair task is
general
(ie:
wiring
and
harness
repair), the repair task is cited in the
Reference Information column.
Male connectors on paving machine
most often house female terminals
(receptacles, jacks). Mating female
connectors house male terminals
(plugs). Plug/jack nomenclature in
text and diagrams is based on nature
of
connector
terminals
(male
or
female),
not
on
appearance
of
connector housing.
Refer to paragraph 7.21 for harness and lead wire repair.
Throughout this diagnostic procedure, a simplified
schematic of the circuit under test is shown. Reference
electrical schematic at back of manual for complete
circuit wiring.
Diagnostic Index
Fault Location
Page
Horn Circuit Diagnostics ...................................................................
2-130
Ignition/Emergency Stop Circuit Diagnostics ....................................
2-136
Flow Gate Control Circuit Diagnostics ..............................................
2-174
Panel Gauge Circuit Diagnostics ......................................................
2-186
High Temperature Shutoff Circuit Diagnostics .................................
2-218
Cold Start Control Circuit Diagnostics ..............................................
2-230
Engine Throttle Control Circuit Diagnostics ......................................
2-236
High Speed Shift Circuit Diagnostics ................................................
2-240
Control Handle, Brake, and Stop/Resume
Circuit Diagnostics .....................................................................
2-244
2-129
