Truck Lighting Parts Dammam

Lamp positions and the bulbs that go in them

Bulb types vary by model and year, so treat the table as a guide and check the marking on your old bulb.

Headlamp units: what fails and when to replace the whole lamp

Bulbs are the cheap part. The headlamp unit is the real repair: the lens, the reflector, the mounting tabs and, on many trucks, the levelling motor that adjusts the beam height. Polycarbonate lenses are light and impact-resistant, but airborne sand pits them and ultraviolet light yellows them, so a lens that looks like frosted glass throws light in the wrong places. When the reflector inside has peeled or burnt, replacing the bulb changes nothing and the whole unit should go.

Broken mounting tabs are another common reason for replacement. A headlamp that is not held rigidly vibrates, blows bulbs and points at the wrong place, so replace the unit and have the beam aim checked afterward.

Why lamps fill with moisture in a hot, humid climate

Lamp housings breathe through a vent. When a hot lamp is suddenly cooled by rain, a wash or evening air, it draws in humid air, which condenses on the cool lens. A little mist that clears within an hour is normal. Standing water, or mist that stays, means a cracked housing, a failed seal or a blocked or missing vent, and the moisture will corrode the connector and the bulb holder if left.

Fit new lamps with their seals in place and vents open, and keep pressure washers away from lamp seams. Drying out and re-sealing a lamp is rarely reliable, and a wet connector is often the real reason for the lamp that goes out on wet mornings.

Aiming headlamps after a replacement

A new headlamp is not finished until it has been aimed. Park the truck on level ground facing a wall or an aiming screen, in the loading condition the manufacturer specifies and with the tyre pressures correct, and adjust each beam to the specified cut-off height and direction. A lamp aimed too high dazzles oncoming drivers, and one aimed too low shortens the driver's view at speed. On trucks with electric levelling, confirm that the motor moves the beam through its full range and returns it to the zero position.

Making bulbs last in heat and vibration

• Handle a halogen bulb by its base. Skin oil on the glass creates hot spots that shorten its life.
• Seat the bulb fully and check the retaining clip, since a bulb that can move will fail early.
• Replace headlamp bulbs in pairs, so that both sides give the same light.
• Check the charging voltage. A regulator fault that pushes the system voltage too high shortens bulb life dramatically.
• Put a small amount of dielectric grease on the connector, not on the bulb, to keep moisture out.
• Fix any loose or cracked lamp mount at once, because vibration is a bulb's worst enemy.

LED or halogen? What to check before switching

• Voltage: confirm the LED unit is rated for 24 volts, or for a range that includes it.
• Bulb-out monitoring: some trucks measure lamp current and report a fault when a low-power LED replaces a halogen bulb. Complete LED lamp assemblies designed for the truck avoid this.
• Optics: a retrofit LED bulb in a reflector designed for a halogen filament can scatter light and dazzle oncoming drivers. Buy a lamp designed around LED light sources instead.
• Approval: look for the approval marking on the lens of headlamps and signal lamps.
• Heat: LEDs run cooler than halogen, but their electronics still need airflow and a sealed lamp that stays dry.

Night runs, dust and animals: the local lighting case

Long night hauls involve dark stretches with little roadside lighting, sand blowing across the carriageway, and, on rural roads, camels and other animals that appear without warning. Dark stretches of highway are a good example, and the same applies to night departures from Dammam's port and industrial areas, where drivers set off before dawn to beat the traffic and the heat.

Clean lenses matter as much as strong bulbs. Wash lamps with water before wiping, because dry wiping grinds dust into the lens, and replace fog lamps that have lost their glass or their seal. Vehicles working industrial estates at night also depend on marker lamps and rear reflectors to be seen against unlit machinery and stockpiles.

Trailer lighting: the half people forget

A trailer's rear cluster gets damaged more often than the tractor's lamps, mostly when reversing to a dock. The lamps, the cable and the plug must all work together, and a corroded plug or a broken wire often looks like a faulty lamp. Send us a photo of the whole cluster from behind and the type of plug, and we will match the lamp and tell you what to check on the cable.

How to order the right lamp

• A photo of the lamp from the front and the back, showing the connector.
• The part number on the lamp housing, if there is one.
• Which side of the truck the lamp fits, and whether you need a pair.
• The number of pins in the connector and whether the lamp has a levelling motor.
• For bulbs, the base type and wattage printed on the old bulb.

Lighting questions from drivers and fleets