2020 Ford F-150 Bulb Sizes (Headlight, Tail, Fog)

Quick reference

The 2020 Ford F-150 offers a wide range of lighting configurations, largely dependent on the trim level and optional packages. Understanding these variations is crucial when looking to replace or upgrade your truck's lighting. The base XL and XLT models typically come equipped with halogen bulbs for most exterior lighting, while higher trims like the Lariat, King Ranch, Platinum, and Limited often feature advanced LED lighting systems, particularly for headlights and taillights.

For low beams, halogen-equipped F-150s use an H11 bulb. However, many F-150s feature OEM LED headlights which are not designed with replaceable bulbs; rather, the entire headlamp assembly would need to be replaced if the LEDs fail. Some higher trim levels might also come with Xenon High-Intensity Discharge (HID) projector headlights, which utilize a D3S HID bulb for the low beam, offering superior light output and a distinct beam pattern. High beams on halogen setups commonly use a 9005 bulb. Similar to the low beams, LED-equipped F-150s integrate the high beam functionality into the OEM LED assembly.

Fog lights on the 2020 F-150 most commonly use an H11 bulb, regardless of whether the headlights are halogen or LED, though some premium trims may feature integrated LED fog lights. Daytime Running Lights (DRL) can vary significantly. On halogen headlight equipped trucks, the DRL function is often integrated into the high beam bulb using a lower voltage, or sometimes a dedicated fuse-type bulb (42mm Fuse). LED-equipped F-150s have dedicated LED DRL strips that are part of the headlamp assembly.

Turn signals are generally consistent across trims. The front turn signals use a WY21W amber halogen bulb. Rear turn signals, brake lights, and tail lights on most halogen-equipped F-150s share a 3157 bulb. It's important to note that if your F-150 has OEM LED taillights (common on higher trims), these functions are integrated LEDs and do not have replaceable bulbs. The reverse lights typically use a 921 halogen bulb. License plate lights are commonly a 194 bulb. Front side markers often use a 194 bulb, while rear side markers are typically integrated LEDs.

Inside the cabin, the dome and map lights in both the front and rear typically use a 578 festoon bulb. These are generally consistent across all trim levels, making them a common target for LED upgrades due to their ease of access and noticeable improvement in brightness.

LED vs Halogen Upgrade Considerations

Upgrading from halogen to LED bulbs in your 2020 Ford F-150 can significantly improve visibility and give your truck a more modern look, but there are a few important considerations. The F-150's electrical system is sensitive, and simply swapping out halogen bulbs for LEDs can sometimes lead to issues.

CANBUS Errors: Modern vehicles like the F-150 utilize a Controller Area Network (CANBUS) system to monitor electrical components. LED bulbs draw significantly less power than their halogen counterparts, which can trick the CANBUS system into thinking a bulb is out. This often results in a "bulb out" warning light on your dashboard, hyper-flashing turn signals, or even flickering lights. To prevent these CANBUS errors, you will likely need LED bulbs with built-in CANBUS decoders or separate load resistors/decoders. These devices simulate the electrical load of a halogen bulb, satisfying the CANBUS system.

Adapters Needed: For headlights and fog lights, while the bulb base might be the same (e.g., H11), the physical size of some aftermarket LED bulbs, especially those with larger heatsinks or cooling fans, might not fit within the existing housing or require slight modification. Ensure you check the dimensions of any aftermarket LED bulb against the available space in your F-150's light housing. Additionally, some LED kits may come with specific connectors or require minor wiring adaptations.

Beam Pattern: With projector-style headlights (common for HIDs and some LED setups), carefully selected LED bulbs can work well. However, when replacing halogen bulbs in a reflector housing (common on base models), the different light output pattern of an LED can sometimes create glare for oncoming drivers or result in a less effective beam pattern. Look for LED bulbs specifically designed for reflector housings to maintain a proper beam pattern.

How to Replace Each Bulb

Replacing bulbs on your 2020 Ford F-150 generally ranges from simple to moderately challenging. Always ensure your vehicle is off and the parking brake is engaged before starting.

• Low Beam/High Beam/DRL (Halogen): Access is typically from behind the headlight assembly. You may need to remove a plastic cover or air intake tube for better access. Twist the bulb counter-clockwise to remove, unplug the connector, and reverse the process for installation.
• Fog Light: Often accessible from underneath the front bumper or by removing part of the fender liner. Twist and pull to remove the bulb, then unplug the connector.
• Front Turn Signal: Usually accessed from behind the headlight assembly, similar to low/high beams. Twist the socket and pull it out, then replace the bulb.
• Rear Turn Signal/Brake Light/Tail Light/Reverse Light (Halogen): Access these by removing the taillight assembly. This typically involves removing two screws on the inside edge of the tailgate opening, then gently pulling the assembly straight back to release clips. Once the assembly is out, twist the bulb sockets to remove them.
• License Plate Light: Accessed by removing two small screws holding the clear lens cover in place, or by twisting the entire socket from the bumper.
• Front Side Marker: Usually twists out from the back of the headlight housing.
• Dome/Map Lights: Carefully pry open the clear lens cover with a plastic trim removal tool (or a small flathead screwdriver wrapped in tape to prevent scratching). The festoon bulb simply clips into place.

Common Lighting Issues for this Generation

While the 2020 Ford F-150 is generally reliable, some lighting-related issues can arise:

• Moisture in Headlight/Taillight Assemblies: Condensation or moisture buildup inside the light housings is a relatively common complaint. While a small amount of fogging is sometimes considered normal, excessive moisture can lead to bulb failure or damage to LED components. This often indicates a compromised seal.
• LED Headlight/Taillight Failures: On higher trims with OEM LED lighting, individual LEDs or entire light strips can occasionally fail. Since these are integrated units, repair usually involves replacing the entire headlight or taillight assembly, which can be costly.
• Hyper-flashing Turn Signals: If you have upgraded to aftermarket LED turn signal bulbs without proper load resistors, you will almost certainly experience hyper-flashing, where the turn signals blink very rapidly, indicating a perceived "bulb out" to the vehicle's computer.
• Flickering Aftermarket LEDs: Poor quality aftermarket LED bulbs or improper installation can lead to flickering issues, especially in headlights or fog lights. This can be due to insufficient power stability, CANBUS incompatibility, or poor connections.

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