WIRE CODE IDENTIFICATION
Each wire shown in the diagrams contains a code
(Fig. 3) which identifies the main circuit, part of the
main circuit, gauge of wire, and color. The color is
shown as a two letter code which can be identified by
referring to the Wire Color Code Chart (Fig. 4). If the
wire has a tracer and it is a standard color an aster-
isk will follow the main wire color. If the tracer is
non-standard the main wire color will have a slash (/)
after it followed by the tracer color.
CIRCUIT IDENTIFICATION
All circuits in the diagrams use an alpha/numeric
code to identify the wire and its function. To identify
which circuit code applies to a system, refer to the
Circuit Identification Code Chart. This chart shows
the main circuits only and does not show the second-
ary codes that may apply to some models.
LOCATING A SYSTEM
To locate a system or component in the diagrams,
refer to the alphabetical index at the front of the di-
agrams. Determine the diagram sheet number. Sheet
numbers are located at the lower right or left handcorner of each sheet.Page numbers at the top of
the page do not apply to diagram sheets.
The index identifies the main system and all com-
ponents that relate to that system. There are also
sections of the index that identify specific compo-
nents only (for example modules, lamps, etc.). Refer
to a components name in the index if you are unclear
as to what a system may be called.
Diagram sheets are arranged starting with the bat-
tery and fuses. Then working into charging, starting,
and ignition systems. After this they start at the
front of the vehicle and work to rear. The diagrams
end with connector identification pages.
COMPONENT IDENTIFICATION
When looking for a components location in the vehicle
refer to the Component Identification section index.
This section shows the wire harness routing and the
components location in the vehicle. When using this sec-
tion refer to the wiring diagrams for the general loca-
tion of the component. Then use the component
identification index to locate the proper figure number.
SPLICE LOCATIONS
Splice locations are indicated in the diagrams by a
diamond with a splice circuit code within it (Fig. 5
example 1). If there is more than one splice per cir-
cuit a small box will be connected to it with the
splice number in it (Fig. 5 example 2).
To locate a splice in the wiring harness determine
the splice number from the wiring diagrams then re-
fer to the splice location index. This section shows
the general location of the splice in the harness.
Fig. 2 Secondary Ignition Wiring 4.0L
Fig. 3 Wire Color Code Identification
Fig. 4 Wire Color Code Chart
8W - 2 WIRING DIAGRAMSJ
CONNECTORS
The connectors shown in the diagram sheets are
viewed from the terminal end unless otherwise speci-
fied. For viewing bulkhead, powertrain control module,
and transmission control module connectors refer to the
rear of the wiring diagrams. This area shows major con-
nectors and identifies pin and cavity information.
The connectors shown in the diagrams are identi-
fied in two ways. The first is an actual view of the
connector. This view shows the connector and which
cavity the wire is in.
The second way is with the use of arrows to indicate
the connector. This is done when the connector is to
large to be shown on the diagram page. A box placed
next to the connector identifies the connector and the
cavity the wire is in. In certain instances there may be
more than one connector in the same location. When
this happens the connector identification box will have a
number placed in it. Refer to the rear of the diagrams
for a complete pin out of the connector.
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are
six steps which can aid in the procedure. The steps
are listed and explained below.(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are
in the same circuit as the problem area. Refer to the
wiring diagrams fuse application chart for circuit
identification.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem.
(6) Verify proper operation. For this step check for
proper operation of all items on the circuit repaired.
Refer to the wiring diagram fuse application chart for
circuit identification.
FUSIBLE LINKS
Vehicle wiring harnesses are equipped with fusible
links to protect against harness damage in the event
of a short in the system. Fusible links are color coded
to indicate wire gauge and size. Refer to the fusible
link chart for color and gauge identification (Fig. 6).
Fig. 5 Wiring Splice Examples
Fig. 6 Fusible Link Chart
JWIRING DIAGRAMS 8W - 3
