2024 Volvo VNL Bulb Size Guide (Headlight, Tail, Fog)

Maintaining proper visibility in a heavy-duty commercial truck is crucial for safety and compliance. As an ASE-certified master technician, I have seen how critical it is to have the right lighting on the road. The 2024 Volvo VNL represents the pinnacle of modern long-haul engineering, and its lighting system is a mix of advanced LED technology and traditional fleet-spec components depending on your specific trim and options package.

Below is your comprehensive guide to the 2024 Volvo VNL bulb sizes, covering everything from headlights to interior dome lights.

Quick reference

Note: Volvo has made full-LED headlight and taillight assemblies standard on most 2024 VNL configurations. If your truck has LED assemblies, the bulbs are generally non-replaceable, and the entire housing must be swapped if it fails. Base or fleet-spec models may still utilize halogen setups.

LED vs halogen upgrade considerations

Many fleet operators and owner-operators look to upgrade their standard halogen bulbs to LEDs for better nighttime visibility and longer lifespan. If your 2024 Volvo VNL came with halogen headlights (H11/H9), upgrading to LED drop-in bulbs is possible, but requires some care.

Modern Volvo trucks utilize an advanced multiplex wiring system and a strict CANBUS network to monitor bulb outages. If you install standard aftermarket LED bulbs, the truck's computer will likely detect a drop in electrical resistance and trigger a "Bulb Out" warning on the dash, or cause the lights to flicker. To prevent this, you must use LED bulbs with built-in CANBUS decoders or install inline load resistors. Additionally, make sure the LED heat sinks or cooling fans have enough clearance behind the headlight housing, as space can be tight on some VNL front ends.

How to replace each bulb

Here are a few professional tips for replacing the bulbs on your 2024 Volvo VNL:

• Low/High Beam Headlights (Halogen): Accessing the headlight bulbs requires tilting the hood. Behind the headlight assembly, you will find dust covers. Twist the cover counterclockwise to remove it, unplug the wiring harness, and twist the H11 or H9 bulb out. Do not touch the new halogen bulb glass with bare hands, as skin oils will cause premature failure.
• Fog Lights: Fog lights are accessible from beneath the bumper. You may need to remove a small splash shield depending on your aerodynamic package. Twist the H11 bulb counterclockwise to remove.
• Front Turn Signals/Side Markers: For incandescent fleet models, the 3157 front turn signal is accessed via the rear of the headlight housing, similar to the headlights. Side markers on the wheel arches usually require a simple Philips screwdriver to remove the lens and pull the 194 bulb straight out.
• Tail, Brake, and Reverse Lights: Most rear lighting on the VNL tractors is housed in the chassis-mounted tail light boxes. Remove the four screws holding the polycarbonate lens in place. Pull the old 3157 or 3156 bulb straight out of its socket and push the new one in. Ensure the rubber gasket is seated properly when reinstalling the lens to prevent water intrusion.
• Dome/Map Lights: Use a plastic trim tool to gently pry the overhead console lenses down. The DE3175 festoon bulbs snap into spring clips, while the 194 bulbs pull straight out.

Common lighting issues for this generation

While the 2024 Volvo VNL is highly reliable, the rigorous environment of over-the-road trucking takes its toll. The most common lighting issue on this generation is water intrusion in the rear tail light boxes or standard fog lights, which can short out traditional incandescent bulbs. Additionally, wiring harness chafing near the chassis pivot points can cause intermittent ground issues, leading to dim or flickering tail lights. If you replace a bulb and it still doesn't work, always check the ground connections on the frame rail before assuming the new bulb is defective.

If you are dealing with complex CANBUS errors, integrated LED assembly replacements, or wiring faults that you cannot trace on the road, it's best to seek professional assistance.

Find a trusted shop on Repairius.