How to Find and Use These Diagrams

Diagrams are presented in three main categories:
^ Power Distribution Diagrams
^ System Diagrams
^ Grounds Diagrams

Note: All wiring connections between components are shown exactly as they exist in the vehicles. It is important to realize, however, that no attempt has been made on the diagram to represent components and wiring as they physically appear on the vehicle. For example, a 4-foot length of wire is treated no differently in a diagram from one which is only a few inches long. Furthermore, to aid in understanding electrical (electronic) operation, wiring inside complicated components has been simplified.

Complete Circuit Operation
Each circuit is shown completely and independently in one set of diagrams. Other components which are connected to the circuit may not be shown unless they influence the circuit operation.

Current Flow (1)
Each set of diagrams normally starts with the component that powers the circuit such as a fuse or the ignition switch. Current flow is shown from the power source at the top of the diagram to ground at the bottom of the diagram. In order to concentrate on the essential parts, power supply and ground connections are sometimes simplified by a dashed line in the diagrams.

Switch Positions (2)
Within the diagram, all switches, sensors and relays are shown "at rest" (as if the Ignition Switch were OFF).

Splices (3)
An arrow indicates that the splice is not shown completely. If the splice is not shown completely in the diagram but is complete within the set of diagrams, the number of the diagram where the splice is completed is indicated next to the arrow.

Boxes (4)
A thin dashed box on a diagram indicates a pan of the circuit which is only present for a particular vehicle model, country, or option. These qualifiers are shown next to the box on the diagram.

Component Names and Notes (5)
Component names are placed on the right hand side of each component. Any notes that describe switch positions or operating conditions follow the name. Descriptions of the internals of the component are also included here.

Component Identification Numbers (6)
Each component on each diagram has a component identification number located to the upper right hand side of the component. By finding this number in the A-Z Component List, the Component Location description for that component can easily be found.

Fuse And Relay Information:

Fuse and Relay Information
Fuse Box/Locations and Relay Box/Locations contain views of the fuse/relay box in which all fuses and relays are identified.

Power Distribution:

Power Distribution
"Power Distribution" shows the current feed circuit. The Current path is shown from the battery to the ignition switch and to all fuses.

Fuse Circuits:

Fuse Circuits
The first diagram in "Fuse Circuits" shows the circuits protected by each fuse. The circuit is traced from the fuse to the component. All details (wires, splices, connectors) between the fuse and the first component are shown.

Any subsequent diagrams will show circuits feeding the fuse, all the way back to the battery.

Ground Distribution:

Ground Distribution
"Ground Distribution" contains the diagrams that show the complete details for each ground connection or main ground splice. This is useful in diagnosing a problem affecting several components at once (poor ground connection or ground splice). All details (wires, splices, connectors) between the ground point and the components are shown. These ground connection details are shown here in order to keep the individual sets of diagrams as uncluttered as possible.

Splices with a large number of wires may be split in order to improve the graphic representation. A thin line is used to indicate the unity of the splice. The splice is then marked with the additional text "partial".

Component Identification Information
Component Identification Information consists of
(1) A-Z Component List,
(2) Component Location Views, and
(3) Connector views (Faces).

The A-Z Component List helps the user find where the various items depicted on the diagram can physically be found on the vehicle. A brief written description of the location is given.

The Component Location Views show the components and their connecting wires as they can be found on the vehicle.

The Connector Views show the views of the pins and/or cavities of all connectors. The pin and cavity sides are shown separately as if the connector were disconnected. The color of the connector housing is indicated next to the connector number.

Vacuum Motor Operation
Vacuum motors operate like electrical solenoids, mechanically pushing or pulling a shaft between two fixed positions. When vacuum is not applied, the shaft is pushed all the way out by a spring.

Some vacuum motors can position the actuating arm at any position between fully extended and fully retracted. The Servo is operated by a control valve that applies varying amounts of vacuum to the motor. The higher the vacuum level, the greater the retraction of the motor arm. Servo Motors work nearly the same way as two-position motors, except for the way the vacuum is applied. Servo Motors are generally larger and provide a calibrated control.

A double diaphragm motor has three positions (it is actually two motors in one housing). When the top port gets vacuum, the shaft pulls halfway in. When both ports get vacuum, the shaft pulls all the way in.

WARNINGS
^ Always wear safety glasses for eye protection.
^ Use safety stands whenever a procedure requires being under a vehicle.
^ Be sure that the Ignition Switch is always in the OFF position, unless otherwise required by the procedure.
^ Set the parking brake when working on any vehicle. An automatic transmission should be in PARK. A manual transmission should be in NEUTRAL.
^ Operate the engine only in a well-ventilated area to avoid danger of carbon monoxide.
^ Keep away from moving parts, especially the fan and belts, when the engine is running.
^ To prevent serious burns, avoid contact with hot metal parts such as the radiator, exhaust manifold, tall pipe, catalytic converter and muffler.
^ Do not allow flame or sparks near the battery. Gases are always present in and around the battery. An explosion could occur.
^ Do not smoke when working on a vehicle.
^ To avoid injury always remove rings, watches, loose hanging jewelry and avoid wearing loose clothing.

circuit Numbering:

Circuit Numbering and Wire Identification
Circuit Numbering:
Ford has introduced a world-wide uniform system for circuit numbering and wire identification.
The system is called Function, System-Connection, or FSC for short.
FSC was developed mainly to assist in vehicle development and production processes, but is also helpful in troubleshooting electrical circuits.
Function:
The first two digits identify the function of the wire. In this case, the function code includes the letter "S" to indicate it is an additionally switched function. The function part of the circuit number is the most helpful to the technician in troubleshooting a circuit.
System-Connection (including branch):
Systems are related to subsets of the vehicle circuitry. Immediately following the system letter code is the connection number specific to that system. A branch identification is used to differentiate wires in one connection with the same function.

Wire Identification (wire colors):
The wire identification consists of a basic color and an identification color, and is determined directly from the wire's circuit number. In the schematics the wire colors are indicated next to the wires.
The basic and identification colors are abbreviated using the international norm IEC 757.
Each function code has a specific basic color associated with it. A colored stripe is used to differentiate several wires with the same function within one component connector.

Wire Identification Example:

Using the circuit number and wire identification used in the Wire Identification Example, we know the following information about the wire:

Function: 31 = Ground
S = Additionally switched circuit
System: AC = Headlamp leveling
Connection: 3 = Switch connection
A = Branch
Size: 1.5 = 1.5 sq.mm
Color: BK = Basic color black (determined by function 31)
RD = Identification color red (red stripe).

Circuit Identification Charts