As cars continue to evolve, so do their auto-electrical systems. We’re all aware that our car’s headlights and heating are part of the electrical system; but have you ever really thought about just how many different components make up the modern motors car’s complex auto-electrical system?

The Battery

A car battery is a type of rechargeable battery that supplies electric energy to a car’s primary electrical system. Car batteries usually supply power to the starter motor, the lights, and the ignition system of a vehicle’s engine. Most car batteries are a lead-acid type, which provides a 12 volt charge. Heavy vehicles such as trucks or tractors may have two batteries in series for a 24 volt system, or may have parallel strings of batteries. Lead-acid batteries consist of plates of lead and separate plates of lead dioxide, which are submerged in a solution of around 35% sulphuric acid and 65% water. This combination causes a chemical reaction which is harnessed to produce electricity. Like all batteries, car batteries can only produce a limited amount of electricity before the need to be recharged.

Alternator

The alternator is a small electrical generator which is driven by the revolutions of the car’s engine. An alternator produces electricity in the form of alternating current – or AC – which is converted internally to direct current – or DC. The alternator is used to recharge the car’s battery and to power the remainder of the car’s electrical components and accessories. Once your car has started, it’s the alternator that keeps everything else going.

Starter Motor

The starter motor is the other major component in your car’s electrical system. The starter motor is only used when you start your car but it is the single largest power user and most critical to your car’s operation. The starter motor is a large direct current – or DC – motor that turns the engine’s crankshaft to start the internal combustion process. The internal combustion process is self-perpetuating, unless your car stalls and then you’ll need the starter motor again. When you first start your car in the morning and you can hear it "turning over", that’s your starter motor turning the crankshaft.

Electronic Fuel Injection

Since the early 1990s, almost all petrol-powered cars sold in developed markets use electronic fuel injection (EFI). This introduction has been mainly as a way of controlling fuel efficiency and also pollution emissions. Electronic fuel injection is a very accurate means of pushing – or injecting – petrol into an internal combustion engine. The main difference between carburettors used in older cars and fuel injection, is that fuel injection pushes the fuel into the engine, while a carburettor sucks the fuel into the engine’s airstream. While fuel injection systems have existed for a long time, modern electronic fuel injection systems are designed specifically for the type of fuel being used and will be specific to petrol or diesel engines. Some electronic fuel injection systems are even specialised to different grades of petrol or diesel.

Other components and accessories

In addition to lights and air-conditioning, an ever-increasing array of components now form part of your vehicles electrical system. While many of these items where once consider optional extras or accessories, they are more and more considered an integral part of the motor vehicle.

These include:

• Electronic locking and immobilisation systems, including car alarms, keyless entry and steering immobilisation.
• Audio visual equipment, including CD and DVD players, radios, speakers and LCD screens.
• Dashboard components and screens, including gauges and on-board computers.
• Mobile phone kits, including hands free sets and chargers.
• Heaters and defrosters.

Auto electrical services specialise in the installation and repair of all these components and more. Auto electricians are highly specialist tradesmen who are able to diagnose and assess problems with your cars wiring or electrical systems, as well as carry out maintenance and repairs. Today, your car’s electrical system controls almost every driving function. That’s why ensuring these systems and components are working properly is the only way to ensure your car runs well. While it can be tempting to try installing those new speakers yourself, it’s often cheaper in the long run to let a professional do it right the first time.