How Do You Read Automotive Wiring Diagrams?
Automotive wiring diagrams outline how the electrical system is laid out. Each symbol in the automotive wiring diagram represents a power source, device to be powered, switching mechanism, electrical conductor, or electrical ground. Older automotive wiring diagrams utilize symbols that look somewhat like the devices they represent (such as headlamps). Newer automotive diagrams, however, utilize ANSI (American National Standards Institute) or IEC (International Electrotechnical Commission) standard electrical symbols. Open the wiring diagram on a flat surface. Trace the schematic lines going from the positive battery terminal to each device. Each device in the schematic connected by a line to the positive terminal on the battery is powered by that battery, unless otherwise noted. Trace the schematic lines going from the negative battery terminal to each device. These connections represent the current path back to the battery from each powered device, unless otherwise noted. Trace any de
