How to Use the Circuit Diagrams

How To Use The Circuit Diagrams

All of the information in this folder is intended for use with the Electrical Reference Library booklet.

The circuit diagrams are presented with Power and Earth distribution first, followed by individual circuits for each electrical system on the car.

Power Distribution
The Power Distribution diagram shows the connections from the battery to the engine and passenger compartment fuseboxes. It also shows the internal circuitry of the fuseboxes.







The fuse box details are followed by independent functionally specific circuits and then a Splices and centre taps section outlining the way in which internal harness splices and centre taps distribute power in the harnesses. This information should be used during diagnosis of electrical faults to check for symptoms in associated circuits and narrow down the search area.

Earth Distribution
The ground distribution section comprises a number of Headers and Splices tables. These are used in a similar manner to those in Power Distribution; to narrow the search area by checking for fault symptoms in associated circuits.

Splices and centre taps
Header and splice tables present the joint(s) and wiring up to the first component. Splices are identified by a number with an alphabetical prefix and the wire colour.

The splice information shown on individual system circuits is not complete. Always refer to the splices circuit for complete information on each splice.

Wire attributes
Additional information (separated by a ',') is shown alongside the wire colour:
Wire gauge - the cross-sectional area of the wire in square millimetres. This is included to help you select the correct wire during harness repair.

Some wires do not have a gauge shown, these wires are of unique construction and will have a three or four letter code printed after the colour code, eg MAB. The code identifies the type of wire for manufacturing purposes. Usually, only the first two characters have significance in service, but in some instances the third character also becomes significant, see table.

Wire type
The following table list the wire type codes together with an explanation of their meaning.







Wire length (Power & Earth Distribution only)
The length of the wire in millimetres. This can be used to locate internal harness splices; look for the shortest wire between the joint and connector. For example, it can be seen that C574-4 is 150 mm from joint A82.

Connectors







Header joints are identified by their corresponding connector number with a numbered suffix to indicate the pin-out detail of the wire, i.e. C289-1 identifies connector 289, pin number 1. Wire insulation colour is identified in the normal way. Where wires have a predominant colour with a secondary colour stripe, the main colour is identified first, i.e. LGS - Light Green with a Slate stripe.

Line Types







This means the wire connects to another circuit.







The cup and ball symbol indicates the male and female halves of connector.

A. Plug on lead (Flylead) wired directly to the component.
B. Connector plugs directly into component.

Components







The name or description of the component is shown. A dotted outline indicates that the component is not shown in its entirety.

Earth points







Earth points are identified with an eyelet symbol and a connector number, except where components are grounded through their fixings, when only the eyelet is shown.


Fuses and Diodes







Fusible links (A) and current rated fuses (B) are identified as shown.

The direction of the arrow in a Diode symbol (C) indicates the direction of current flow. The Zener diode (D) - prevents current flow until a precise voltage is reached.