2018 Ford Transit Bulb Size Chart & Replacement Guide

As an ASE-certified master technician, I’ve seen my fair share of 2018 Ford Transit vans roll through the shop. Whether you’re running a delivery fleet, outfitting a camper van, or just hauling cargo, keeping your Transit’s lighting in top shape is a safety requirement you can't ignore. Finding the right replacement bulbs can be confusing given the sheer size of the vehicle and the different configurations available.

Here is a comprehensive breakdown of the bulb sizes for the 2018 Ford Transit, along with replacement tips and upgrade considerations.

Quick Reference: 2018 Ford Transit Bulb Sizes

Note: The 2018 Ford Transit standard configuration uses halogen housings. Always check your owner's manual or pull the original bulb if your van was fitted with an aftermarket upfitter package.

LED vs Halogen Upgrade Considerations

The standard 2018 Ford Transit comes equipped with basic halogen bulbs. Upgrading to LEDs can drastically improve nighttime visibility for drivers working late shifts or navigating unlit rural roads, but it isn't always a simple plug-and-play process.

CANBUS Errors and Flickering: The electrical system on the Ford Transit is sensitive to voltage changes. LEDs draw significantly less power than halogens, which can trick the van's Body Control Module (BCM) into thinking a bulb is burnt out. This often results in a "bulb out" warning on your dash, or flickering headlights. When upgrading your H11 low beams or H15 high beams, make sure you purchase LED kits that include built-in CANBUS decoders or anti-flicker harnesses.

Turn Signal Hyper-Flashing: If you swap your 3157 turn signal bulbs to LED, you will likely experience hyper-flashing (rapid blinking). To prevent this, you will need to wire in a 50W 6-Ohm load resistor in parallel with the turn signal circuit.

Dust Covers and Fitment: LED bulbs have bulky cooling fans or heat sinks on the back. The H11 low beam housing on the Transit has a relatively tight dust cover. Ensure you choose a low-profile LED bulb, or look into extended aftermarket dust covers to keep moisture out of the headlight assembly.

How to Replace Each Bulb

Replacing bulbs on the Transit is generally straightforward, but its large size means you might need a step stool.

• Headlights (Low/High/DRL/Turn): Accessing the headlight bulbs requires popping the hood and reaching behind the headlight assembly. Fortunately, Ford left a decent amount of room back there. Twist the dust cap counterclockwise to remove it, unclip the wiring harness, and twist the bulb out.
• Fog Lights: The easiest way to access the H11 fog lights is from underneath the front bumper. You may need to remove a few splash shield clips to get a clear reach to the back of the fog light housing.
• Tail Lights (Brake, Turn, Reverse, Side Marker): Open the rear cargo doors. Along the inside edge of the tail light assembly, you'll see two T25 Torx screws. Remove these, and carefully pull the tail light housing straight back to dislodge the alignment pins. Twist the respective bulb sockets counterclockwise to replace the bulbs.
• License Plate: There are two small screws holding the license plate light housings in place above the license plate. Remove the screws, pull the housing down, and swap the 194 bulb.
• Interior Dome/Map Lights: Use a plastic trim removal tool to gently pry the plastic lenses off the interior roof consoles. Be gentle; the plastic tabs can become brittle in extreme heat or cold.

Common Lighting Issues for this Generation

While the 2018 Transit is highly reliable, the lighting system does have a few quirks:

1. Tail Light Water Intrusion: A known issue with this generation of Transit is water leaking into the rear tail light housings. The foam gasket behind the housing can degrade, allowing water to pool at the bottom, which shorts out the lower reverse bulb or causes premature failure of the brake light. If you notice condensation, you may need to reseal or replace the housing.
2. H15 High Beam/DRL Burnout: Because the H15 acts as both the Daytime Running Light and the High Beam, it runs almost constantly. Don't be surprised if you find yourself replacing these more often than your low beams.
3. Corroded License Plate Sockets: Due to the aerodynamic draft at the rear of the large van, road salt and grime tend to coat the rear doors. This can lead to corrosion in the license plate bulb sockets.

If you don't have the time to tackle these lighting upgrades or repairs yourself, don't worry. Find a trusted shop on Repairius.