The complete lighting system of a motor car operates on a standard system of 12 volts D.C. Regulations in various countries mean that most cars have similar configurations of front and rear lights, although with some cosmetic differences.
The most powerful lights on a car are normally the headlights. All cars have a pair of headlights, which nowadays have halogen lamps. The halogen bulbs have two filaments, giving two levels of brightness, known as dipped and full beam. With dipped beam lenses on the front of the light deflect the beam downwards onto the road so as not to dazzle oncoming drivers. Also at the front are a pair of side lights. These can be separate units or integral parts of the headlamp unit. They are low wattage lamps, used mainly for parking.
There are at least four indicator lights, one on each corner of the car. These usually have orange coloured lenses and are controlled by the indicator stalk on the steering column. Pushing the stick upwards will cause one pair of lights to flash, for example both right side indicators, whilst pushing it downwards will cause the other pair to flash. Some modern cars have extra indicator lights on the side of the front wing.
At the rear are a pair of tail lights. These have red lenses and are switched on and off with the side and headlights. Also at the rear are the brake lights. These also have red lenses and are controlled by a switch on the brake pedal inside the car, lighting up every time the pedal is pressed. In addition there is normally either one or two reversing lights, having white lenses and being controlled by a switch in the gearbox. These lights have two purposes. Lighting when reverse gear is selected, they illuminate the rear of the car to allow the driver to see where he is going, plus they warn other drivers that the car is travelling backwards. Early models would have these as separate lights but nowadays they are all housed in one assembly, called a light cluster.
A car has many more lights, for example at least one to light each number plate and at least one to light up the inside of the car (known as a courtesy light). There is often a light in the boot (or trunk), one under the bonnet (or hood) and one in the glove compartment. In addition there are sometimes fog lights at front and rear and extra driving lamps. This can make for an expensive time when some countries require the driver to always carry a spare bulb for almost every type of lamp on the car.
