Bulb, headlight for trucks

An incandescent lamp is a component of the truck lighting system. It is used as a light source in headlights and rear lights, side marker lights, stop lamps, turn indicators, and reverse lights. In addition, this element is used in cabin lighting.

Types of incandescent lamps for trucks

By filament type:

• Tungsten. A tungsten spiral is used as a filament. They are inexpensive, have a low light intensity and short service life. Usually, it does not exceed 1,000 hours. They are used in marker lights, turn indicators, and in the equipment inside the cabin.
• Halogen. These are modified tungsten light sources, with a bulb filled with an inert gas containing vapours of halogens. They are often used in low and high beam headlights. Their main advantage is a high light output regardless of the weather conditions. On the average, such components serve for 2,000 - 4,000 hours of operation.

By construction:

• Flanged (prefocus). Bases of such components have a flange limiting the distance between the socket and the filament. This allows placing the latter exactly in the focal point of a reflector. Most often they are used in headlights and fog lamps.
• Bayonet. They have a cylindrical base with symmetrical or offset pins and are often used in turn indicators. A disadvantage of such a design is that the light bulb is not mounted securely enough in the socket.
• Sleeve. They are compact, with bases on both sides of a lamp envelope. They are used in lighting fixtures inside the cabin.
• Wedge base. A metallic base is replaced with a plastic one and contact wires are pressed against the base outside the bulb. They are reliable and are used in marker lights and for instrument panel illumination.

Malfunctions and their causes

Like incandescent lamps for passenger cars, these components may burn out or fail because the tungsten filament or the socket are damaged. Most often this is caused by a power surge when turning on the lighting fixture. Non-observance of the installation procedure may also reduce the component’s service life.

Presence of grease or dust on the glass envelope results in its cracking. Therefore, be sure to wear gloves when replacing the component. If you couldn’t avoid touching the glass, wipe the bulb with an alcohol solution.

How to identify faulty incandescent lamps in trucks

No light when the lighting fixture is switched on suggests the component is faulty. Since the same symptom may indicate other electrical equipment failures, the component should be removed for inspection. In addition, you should measure the resistance, and compare results with the allowable values specified in the manufacturer's catalogue. If light sources have failed in headlights or rear lights, it is recommended to replace them in pairs: right and left one together.

AUTODOC: convenient shopping online

Safety of truck operation largely depends on the correct operation of the lighting system. In our online shop, you can buy incandescent lamps in just a couple of minutes. We offer only top quality products that are needed for repair and maintenance of a vehicle. Experienced specialists of our support service will be happy to give you a piece of advice, help you choose a suitable component and place an order online.