Introduction

The electrical system is basically an efficient means for transmitting power from the engine to the electrical components of the car. It does this with the help of the alternator, which converts some of the engine's mechanical energy into electrical energy. The electrical energy is then carried by wires to the various electrical components such as motors, light bulbs, or electronic control units. The battery in the system supplies electrical power when the engine is not running, and also supplies power to start the engine.

The electrical system is based on negative (-) ground. In other words, the negative terminal of the battery is connected to the car body, and any electrical connection to the body is a connection to ground. This greatly reduces the amount of wire used in the system. Voltage from the battery to the various electrical components is carried by the wiring harness. Most components are then grounded through either direct mounting to the car body or by a ground wire leading to the car body. It is very important for trouble-free operation of the electrical system that the ground connections, including the negative battery cable and the body ground straps, remain sound and free of corrosion.

The connecting terminals on components and wiring harness connectors can be either pins, or sockets into which pins fit. Most terminals are identified with a number stamped next to the pins on the components. On relays, the terminals are also identified by numbers on the relay. Throughout this section, sockets on the relay panel are identified by referring to the terminal which fits into them. The terminal numbers and the location of all the major electrical connections are given in the current flow diagrams in the next section.