How to Read and Use Wiring Diagrams

SYMBOLS USED IN THE WIRING DIAGRAMS

Symbols - Fuses:

Fuses
In the wiring diagrams, every subsystem is generally shown from the relevant fuse in the main fuse box up to the relevant component or components and on to the grounding point or direct chassis connection.

The power supply to each fuse is shown separately in the system group for positive voltage supplies, where the car's main fuse box, ignition switch, etc. are also covered.

Example:
If the supply to a fuse comes from the +30 terminal, the circuit to the fuse in question will be found in the section headed "Power supply, +30 circuit".

Symbols - Grounding Points:

Grounding points
Most of the car's grounding points have a component number consisting of a letter and a number, e.g. G2 or G29. The locations of the grounding points on the car are shown under Diagram Information and Instructions/Ground Information.

Switches, relays and components
Unless otherwise indicated, switches and relays are represented in their unactivated and unenergized state.

When the box around the component is drawn with a solid line, the whole component is shown.

When the box around the component is drawn with a broken line, only part of the component is shown.

Symbols - Crimped Connections:

Crimped connections
To reduce the number of connectors used in the car, the various wiring harnesses contain several crimped connections. They are used as fixed connections and also as connectors. The number of poles in the connector may vary, depending on the market and car version. The maximum version is always shown on the wiring diagram. There is no pin numbering on the connectors.

How they are drawn on the wiring diagram is shown in the above image.