Car Schematic Electrical Symbols Defined We use car schematic electrical symbols to identify both components and how a system operates. We use automotive schematics as a road map to take us to a repaired car. As you read through this page you can refer to the image on the right as a basic automotive circuit. Master Automotive Wiring Diagrams and Electrical Symbols Automotive electrical diagrams provide symbols that represent circuit component functions. For example, a few basic symbols common to electrical schematics are shown as: (1) Switch, (2) Battery, (3) Resistor and (4) Ground. Note the switch symbol displays an open or closed circuit path, which is what an actual switch performs.