2020 Chevrolet Silverado 1500 — Bulb Sizes (Headlight, Tail, Fog)

As an ASE-certified master technician, I regularly see drivers wanting to upgrade or replace the lighting on their trucks. The 2020 Chevrolet Silverado 1500 is a fantastic truck, but its lighting setup can be a bit confusing depending on the trim level you purchased. While base trims like the Work Truck (WT), Custom, and some LTs come with traditional halogen bulbs, higher trims like the RST, LTZ, and High Country feature fully integrated LED assemblies.

Whether you are looking to replace a burnt-out bulb or upgrade your halogen setup to modern LEDs, it’s crucial to know exactly what size you need. Below is the comprehensive bulb size guide for the 2020 Chevrolet Silverado 1500.

Quick reference

Note: Trims with factory LED packages (like LTZ or High Country) use sealed assemblies for headlights, taillights, and fog lights, which cannot be serviced with individual replacement bulbs.

LED vs halogen upgrade considerations

If you have a WT, Custom, or LT trim equipped with factory halogen bulbs, upgrading to aftermarket LEDs is a very popular modification. However, modern trucks like the 2020 Silverado 1500 are heavily reliant on their Body Control Module (BCM) to monitor electrical loads.

• CANBUS Errors & Hyperflashing: The Silverado's computer expects a specific resistance from halogen bulbs. When you install LEDs (which draw much less power), the truck may think the bulb is burnt out. For turn signals, this causes "hyperflashing." For headlights, it can cause flickering or dashboard error messages.
• Resistors and Decoders: To prevent hyperflashing in turn signals, you will likely need to splice in load resistors or buy CANBUS-ready LED bulbs. For H11 and 9005 headlight upgrades, I highly recommend purchasing a kit that includes a CANBUS decoder/anti-flicker harness specifically designed for newer GM trucks.
• Beam Pattern: Always ensure your aftermarket LED headlight bulbs have a rotatable collar so you can properly align the LED chips (they should face exactly 3 and 9 o'clock) to replicate the halogen filament's position and avoid blinding oncoming traffic.

How to replace each bulb

Here are a few quick tips from the service bay for tackling these replacements:

• Low and High Beam Headlights (H11 / 9005): Accessing the headlight bulbs on this generation Silverado requires going through the wheel well. Turn your wheels inward, remove the Torx screws holding the front of the fender liner, peel it back, and reach behind the headlight assembly. Twist the dust cap off, then twist the bulb counterclockwise to remove.
• Fog Lights (5202): These are easiest to access from underneath the front bumper. You may need to remove a plastic splash shield for better clearance. Simply unclip the harness and twist the bulb out.
• Tail, Brake, and Rear Turn Signals (7443): Lower the tailgate and locate the two T15 Torx screws on the inside lip of the bed. Remove them and pull the entire taillight assembly straight back. The bulb sockets twist out easily.
• Reverse Lights (921): Accessed the same way as the tail lights. A quick and highly recommended upgrade is swapping the 921 halogens for LEDs to vastly improve backup camera visibility at night.
• License Plate (194): Reach up behind the rear bumper, twist the socket counterclockwise, and pull the bulb straight out.
• Interior Map/Dome (194 / 578): Use a non-marring plastic trim tool to gently pop the plastic lenses off the overhead console. Be careful not to break the fragile retention tabs.

Common lighting issues for this generation

One of the most common issues on the 2019-2021 Silverado 1500 is moisture intrusion in the factory taillights, particularly on trims with the blind-spot monitoring sensors integrated into the housing. If you notice heavy condensation that doesn't clear up, the assembly seals may be failing.

Additionally, drivers who upgrade to cheap aftermarket LED headlights often complain of radio interference (static on FM/AM stations). This is caused by poorly shielded cooling fans or drivers on the LED bulbs. Always stick to reputable, high-quality lighting brands.

If you are dealing with persistent electrical issues, CANBUS faults, or need a full headlight assembly replaced and aligned, it's best to leave it to the professionals. Find a trusted shop on Repairius.