Car lighting parts

Additional headlights for your car: find out more! Which ones to choose, when to change them, and how much they cost

The lighting system includes lights, lamps, bulbs, and their components. They illuminate the area in front of the car and the inside of the cabin at night time or in bad weather, and act as warnings and signals, for instance by indicating the size of the vehicle to other drivers or warning them about the intention to make a turn or switch lanes.

Design of a lighting system

The main lighting elements are:

• Lights (lamps). These consist of a housing, a reflector, and a diffuser. There are also sockets for securing and powering light sources, namely bulbs. Some types of products have a special screen to form a light beam and a lens to ensure its diffusion. The sockets are connected to the contacts, which are used to power a bulb. There are caps in the rear part of the lamp housing that ensure access to the internal components of the lamp. Gaskets are installed to seal the joint between the headlamps and the body. Some headlamps have a solid design. They are replaced together with light sources. Interior lights don’t have any reflectors.
• Switches. These are used to switch on the corresponding light fixture and to allow the selection of its operation mode.
• Limit switches. Perform the same function as the switches, with the only difference that the devices are switched on automatically after certain conditions are met. These switches are mounted on the brake pedal and gear lever to ensure the automatic activation of the brake and reverse lights respectively.
• Electrical wiring. This is used to supply voltage from the on-board network to the lighting sources.
• Relays. These are an important element of the electrical circuit. They are responsible for the voltage supply to certain parts of the equipment.
• Fuses. These protect the circuit and electrical equipment from voltage spikes.
• Adjusters. They can be manual or automatic. They adjust the direction and the areas lit by the headlights taking into account the vehicle load.

Maintenance tips

• Use only those kinds of bulbs recommended by the car manufacturer. Components that are too powerful will destroy the internal parts of the lamp.
• Make sure that all connectors are securely attached and that the bulb fits tightly into the bulb socket. Unreliable contact can lead to the components burning out.
• Do not clean lamps with a dry cloth. They are easy to scratch. Always remove dirt with a lint-free cloth soaked with water and car shampoo.
• Occasionally tighten the fastenings to reduce the effects of vibration.
• If you drive off-road frequently, apply a special protective film on the headlights and light diffusers.
• Adjust the headlamps after the installation of tyres or wheels of a different diameter. The headlamps have special adjustment screws for this purpose.
• Polish the headlamps from time to time to make the diffuser clear again. It is better to have this done at a garage.

Malfunction symptoms

An obvious sign of a malfunctioning lighting system is the lack of response of the corresponding device to being switched on. If only one lamp doesn’t work, the lamp itself is likely to be the problem. If several lamps simultaneously do not work, you should check the switch or the fuse. Flickering lamps and flashes when running over an obstacle indicate poor contacts in the socket or insecurely fixed connectors. Fogged up lamps may indicate that their vents are clogged or they are no longer watertight. Dim light is often a sign that the reflector is flaking or there are scratches and chafing on the diffuser.

Malfunction causes

Malfunctions of the electrical system, such as burnt out socket contacts and a defective relay or fuse, are usually associated with unstable voltages in the electrical circuit. However, a voltage spike can in turn be caused by a faulty alternator or an attempt to start the car using a battery of another vehicle with its engine running. Many breakdowns occur due to strong impacts caused by collisions.

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Useful information on functions, causes of malfunction, diagnosis and replacement intervals

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