TM 9-2330-356-14
Section VII. MAINTENANCE OF CHASSIS ELECTRICAL SYSTEM
composite light.
(8) Left Rear Composite Light Lead Assembly. This
WARNING
lead (fig. 4-16) is located in the left rear composite light
box. It connects to the wiring harness in two places and to
When troubleshooting an electrical malfunc-
the left composite light.
tion or performing electrical maintenance,
ALWAYS disconnect Intervehicular electrical
(9) Connector Lead Assembly. This lead
cable from semitrailer, and negative battery
(fig. 4-16) is
located in
the left rear composite light box. It
cables at batteries. Failure to follow this warn-
is made up of six different leads, of which two connect to
ing may create a spark and explosion, result-
left rear marker lights, two to the wiring harness, one to
ing In serious injury or death to personnel.
triple marker light lead, and one to left composite light.
a.
General. The chassis wiring of the semitrailer
Repair. Most of the wiring can be repaired without
b.
consists of one wiring harness, seven electrical lead
removing the harness and leads from the semitrailer.
assemblies, and one receptacle assembly. Refer to figures
4-15 and 4-16 for schematic diagram and wire connections
(1) Clean end of harness leads with a damp cloth.
of chassis electrical system. Wiring is as follows:
(2) Check ends of wire harness for frayed
insulation and broken wires. Tape or replace frayed wires.
(1) Receptacle Assembly. The receptacle
(3) Inspect wires for bent, broken, or missing
semitrailer. It connects the electrical system of the towing
terminals. Replace missing or damaged terminals.
vehicle with that of the semitrailer. The main wiring
harness of the semitrailer connects to the receptacle.
c.
Replacement of Chassis Wiring.
(1) Composite Light and Connector Lead
the entire length of the semitrailer through conduit, the
Assemblies Replacement.
left rear composite light box, to the right rear composite
light box. It connects to various leads which in turn
(a) Remove six screws that secure
connect to the lights on the semitrailer.
composite light box cover (fig. 4-23) to the light box.
Remove cover and gasket.
(3) Rear Triple Marker Light Lead Assembly. This
lead (fig. 4-16) is threaded from the triple marker box
(b) Start removing the old lead terminals
through conduit to the left composite light box. There it
one connection at a time. As each lead terminal is
connects to one of six leads of the connector lead
removed, connect the correct lead terminal of the
assembly.
replacement lead before removing the next one. Continue
this process until the old lead is removed and the new one
(4) Right Front Marker Light Lead. This lead
is completely connected into the circuit.
(fig. 4-16) is
threaded from the right front marker box
through conduit to the left side of the semitrailer. There it
(c) Replace composite light cover and
connects into the receptacle wiring, the wiring harness
gasket. Secure with six screws.
and lead from the left front marker light.
(d) Test operation of lights.
(5) Left Front Marker Light Lead Assembly. This
lead (fig. 4-16) connects to the left front marker light and
(2) Triple Marker Light Lead Assembly Replace-
to the right front marker light lead.
ment.
(6) Right Side Marker Light Lead Assembly. This
(a) Remove six screws that secure
lead (fig. 4-16) is threaded from the right center marker
composite light box cover (fig. 4-23) to the light box.
light box through conduit to the left center marker light
Remove cover and gasket.
box. There it connects to the wiring harness and to the left
center marker light.
(b) In the composite light box, locate the
Disconnect this wire from the connector lead assembly
(7) Right Rear Composite Light Lead Assembly.
This lead (fig. 4-16) is located in the right rear composite