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► Halogen lamps have a much longer life and are generally brighter and produce more light per unit of power consumed, but they become very hot during use.

► High-intensity discharge (HID) headlamps produce light with an electric arc rather than a glowing filament.

► Light-emitting diodes (LEDs) have been used for some time in various automotive applications, such as warning indicators and alphanumeric displays.

► One of the advantages of LEDs is that they turn on instantly.

► All lamps or light bulbs have letters and numbers stamped on them that indicate the power consumed by bulb operation at the nominal operating voltage.

► Lighting regulations should always be consulted before modifying or adding to any of the vehicle lighting systems.

► Park, tail, and marker lamps are all low-intensity or low-wattage lamps used to mark the outline or width of the vehicle.

► Brake lights, which may also be called stop lights, are red lights mounted to the rear of the vehicle.

► Reverse lights, also called back-up lights, are the bright white lights on the back of the vehicle that allow the operator to see behind the vehicle when backing up.

► Hazard lights can warn other road users that a hazardous condition exists or that the vehicle is standing or parked in a dangerous position on the side of the road; they normally use the same bulbs as the turn signal indicators.

► The dim or low beam is usually set to the outside of the front, and the high beams are closer to the front center of the vehicle.

► The driving lights are installed on the front of the vehicle and provide higher intensity illumination over longer distances than standard headlight systems.

► Different lighting technologies can be mounted individually, or together, to form comprehensive adaptive lighting systems, otherwise known as smart lighting.

► Auto-leveling headlights use a sensor to monitor the angle of the vehicle to the road.

► In some vehicles, an ambient light sensor determines when light levels are low; this then allows the body control computer to turn the exterior lights on.

► Networking, CAN-bus, or multiplexing light systems eliminate the amount of wire required for the lighting system and are controlled through a main computer.

► Warning lamps provide the vehicle operator with information regarding the operation of the main vehicle systems, such as the vehicle battery charge, oil pressure level, and airbag system status.

► A typical lighting circuit is made up of the battery, fuses or circuit breakers, switches, lamps, and wiring to connect the electrical circuit.

► For motor vehicles and trailers, two red tail lamps operate when the headlight switch is in the park position and the headlight position.

► Daytime running lights (DRLs) automatically operate when the vehicle is running and turn off when the engine stops.

► The layouts of electrical circuits and their components are shown as diagrams made up of symbols and connecting lines.

► Being able to read and interpret electrical circuit layouts can cut a technician’s troubleshooting time in half; this is a skill all technicians need to learn.

► When checking lighting and peripheral systems, be sure to work in a systematic manner or you could miss a faulty bulb or other component.

► If all of the bulbs on one fuse do not work, check the fuse.

► When replacing a bulb, always ensure there is no corrosion in the bulb socket, as this will shorten the life of the new bulb and add resistance in the circuit.