Electrical Wiring Diagrams

use pictorial representations with a mixture of schematic symbols and internal wiring. A linear
diagram may start on one page and continue onto several more a map out individual circuits with
a separate diagram.
Above - A pictorial or map diagram of the electrical system of a 1968 Ford.
Schematic Diagrams
Schematics are line drawings that explain how a system works by using symbols and connecting
lines. Several different standards for schematic diagrams exit DIN and Valley Forge are the most
common. Symbols are used to represent devices or components of both simple and complex
electrical and electronic systems. Schematic diagrams present a great deal of information in a
small amount of space and the reading of schematic symbols requires practice. A logical, stepby-
step approach to using schematic diagrams for troubleshooting begins with the technician's
understanding of the complete system.
Schematic circuit diagrams may be supplemented with diagrams, tables, graphs or descriptions.
Current path are arranged to show signal or mechanical action from left to right and or top to
bottom. Block diagrams are used to represent complex electronic circuitry such as a electronic
control modules. On these devices, no internal circuitry is shown and only inputs or outputs are
depicted. Dotted lines may represent an area or some mechanical action taking place with a
component The two most common types of schematic diagrams used today are:
� Valley Forge
� DIN (Deutsche Institute Norm)