A wiring diagram is a simple conventional image representation of an electric circuit. This shows the circuit components as a simplified form, and the power and signal connections between devices.

Wiring diagrams usually provide information about the relative position and arrangement of devices and terminals on the device, to assist in building or repairing devices. This is not like a schematic diagram, where the interconnection of components in a diagram is usually not in accordance with the physical location of the components on the finished device. The illustrated diagram will show more details of physical appearance, while the wiring diagram uses more symbolic notation to emphasize interconnection of physical appearance.

Wiring diagrams are often used to solve problems and to ensure that all connections are made and everything is there.