2023 International MV Bulb Sizes: Comprehensive Headlight, Tail & Fog Light Guide

As an ASE-certified master technician who frequently works on commercial fleets and medium-duty chassis, I understand that maintaining proper lighting on your work truck is about more than just aesthetics—it’s critical for DOT compliance, safety, and maximizing uptime. The 2023 International MV Series is a robust medium-duty workhorse, but its lighting configurations can vary heavily depending on the specific fleet spec, trim level, and upfitter body.

Below is your comprehensive guide to the bulb sizes for the 2023 International MV.

Quick reference bulb size chart

Note: Depending on your trim level and upfitter body, your MV may be equipped with standard halogen composite housings, factory-sealed LED headlamp assemblies, or specific rear light boxes. Always verify your current bulb type before purchasing replacements.

LED vs halogen upgrade considerations

Many 2023 International MVs roll off the assembly line with basic halogen composite headlights to keep fleet acquisition costs down. Upgrading your forward lighting to LED can drastically improve nighttime visibility, which is highly recommended for drivers working night shifts or traveling on unlit rural routes.

However, there are a few things to keep in mind before swapping out those H11 and 9005 halogens:

• CANBUS/Body Control Module (BCM) Errors: The International MV utilizes a sophisticated multiplexed electrical system (Diamond Logic®). If you install aftermarket LED bulbs without the proper resistance, the truck's BCM may interpret the low power draw as a "burnt out bulb," triggering dash warnings or causing the lights to flicker or shut off entirely. You will likely need CANBUS-compliant LED bulbs or external load resistors.
• Beam Pattern: Halogen reflector housings are designed for halogen filaments. When choosing an aftermarket LED, ensure it features diodes that mimic the original filament location to prevent scattering light into the eyes of oncoming drivers.
• Upfitter Rear Lights: If your MV has a custom body (dump, box, flatbed), the rear lights are dictated by the upfitter. These are usually standard commercial 4-inch round or 6-inch oval sealed LED grommet-mount lights, rather than replaceable bulbs.

How to replace each bulb

Here are a few quick tips for tackling bulb replacements on your MV Series:

• Headlights (Low/High/Turn): The MV features a tilting fiberglass hood. Once unlatched and tilted forward, you have wide-open, unhindered access to the rear of the headlight assemblies. Simply twist the dust caps off (if equipped), disconnect the wiring harness, and twist the H11 or 9005 bulbs counterclockwise to remove.
• Fog Lights: Located in the lower bumper, these can be accessed by crawling under the front bumper. Disconnect the harness and twist the H11 bulb out.
• Cab Marker / Clearance Lights: Factory cab roof lights are typically sealed LED units on the 2023 models. If one fails, you will need to unscrew the entire amber housing, unplug the pigtail, and replace the whole assembly. Make sure the gasket is seated properly to prevent roof leaks.
• Rear Tail / Brake / Reverse: If you have the standard chassis-cab temporary light boxes, standard Phillips screws hold the lenses over the 3157 bulbs. If you have upfitter-installed sealed LED puck lights, use a flathead screwdriver to carefully pry the light out of its rubber mounting grommet, then unplug the 3-prong connector at the back.
• Interior Dome Lights: Use a plastic trim tool to pry the plastic lens off the overhead console. The festoon (211-2) bulbs are held in by spring-loaded metal prongs.

Common lighting issues for this generation

While the 2023 International MV is relatively new, its electrical architecture shares lineage with previous generations. The most common lighting issues usually involve the Diamond Logic system detecting voltage irregularities. If a lighting circuit experiences a short or an open circuit (often caused by corrosion in upfitter wiring at the rear of the truck), the BCM will cut power to that specific circuit to protect the module.

Additionally, because these trucks vibrate significantly more than passenger cars, standard incandescent filaments (like the front 3157 turn signals) are prone to premature failure. Upgrading to vibration-resistant heavy-duty bulbs or LEDs is a smart preventative measure.

Electrical diagnostics on multiplexed commercial trucks can get complicated quickly. If you are dealing with persistent BCM codes, flashing lights, or upfitter wiring gremlins that you can't trace, don't waste time throwing parts at it. Find a trusted shop on Repairius.