The key to reading an automotive engine diagram is to understand the common symbols used as an industry standard. An understanding of the symbols makes the diagrams easy to comprehend.
Common symbols are used throughout the automotive industry so that diagrams can be used to quickly find complex electrical problems on any vehicle. The symbols commonly used indicate switches, batteries, resistors and grounds.
Diagrams also include more complex, advanced symbols and abbreviations specific to a particular vehicle. Abbreviated codes can be used to supply circuit information, current path and flow, and component polarities. To remain consistent, most diagrams list energy and signal flow from the bottom up. Component inputs are listed on the left, and outputs are listed on the right.
On average, an automobile contains approximately 3,000 feet of electrical wire in addition to the various parts that make up an engine and the other components of a vehicle. Diagrams are available for every part under the hood of a car and make automobile repairs and troubleshooting much less complicated. Diagrams help users see how the system functions and offer a valuable resource to auto technicians and DIYers. When combined with a knowledge voltage, resistance and current, diagrams provide a road map of what lies under the hood of a car.