2021 Chevrolet Silverado 1500 — Bulb Sizes (Headlight, Tail, Fog)

Quick reference

Note: The 2021 Silverado 1500 did not use factory HID/Xenon; headlamps are halogen reflector on lower trims or sealed LED assemblies on mid/high trims. Always confirm by VIN or visual inspection, as packages like RST and convenience/safety bundles can change lamp technology.

LED vs halogen upgrade considerations

• Headlights (H11/9005): Quality LED retrofits can reduce current draw and add brightness, but beam pattern and glare are critical. Use bulbs designed for reflector housings and consider anti-flicker/CANBUS adapters if you see pulsing or “lamp out” messages.
• Fog lights (PSX26W/5202): Many owners upgrade to LED; ensure heat-sink clearance in the bumper housing and weather-seal the O-ring. Some trims have sealed LED fogs — those are not bulb-replaceable.
• DRL/turn signals: Switching front/rear turn bulbs (7444NA/7443) to LED may cause hyper-flash. You’ll need load resistors (commonly 6-ohm, 50W per corner) or CANBUS-compatible LED bulbs. Mount resistors to metal away from wiring.
• Interior/map/dome: T10/194 and 31mm festoon LED upgrades are generally plug-and-play. Pick CANBUS-friendly options to prevent faint glow when off.
• Sealed LED assemblies: On trims with factory LED headlamps or taillamps, individual “bulbs” are not serviceable. Repairs typically require replacing the assembly. Consider this when budgeting upgrades.

How to replace each bulb

• Headlight low/high (H11/9005): Turn the wheel inward, remove the fender-liner access fasteners, and reach behind the housing. Twist counterclockwise to remove the socket; avoid touching halogen glass.
• Fog light (PSX26W/5202): Access from below after turning the wheels or removing the lower splash shield. Twist the bulb counterclockwise; ensure the new bulb’s O-ring is seated to prevent moisture.
• DRL: On halogen trucks, the DRL uses the 9005 high-beam bulb — replacement is the same as high beam. On LED trucks, DRL is integrated and non-serviceable.
• Front turn/sidemarker (7444NA/194): Access through the headlamp rear cap or fender-liner opening. Turn the socket 1/4 turn to release. Match amber color for the turn bulb.
• Taillamp (7443/921): Lower the tailgate. Remove the two T- or Torx-screws on the inner edge of the taillamp and pull the assembly straight back. Twist out the sockets: upper/bigger is typically 7443 (stop/turn/tail), smaller clear is 921 (reverse).
• License plate (194): Pry the lens carefully from the bumper/handle trim, twist out the T10 bulb.
• Rear side marker: Part of the taillamp; serviced with the same 7443 on incandescent housings. LED taillamps are assembly-only.
• Interior map/dome: Use a trim tool to pop the lens, pull the 194 wedge straight out or release the festoon clips. Check polarity on LED upgrades.

Always disconnect the battery when working near airbags or sensitive BCM circuits. Verify operation before reassembling trim.

Common lighting issues for this generation

• Hyper-flash after LED turn-signal swaps: Add resistors or use CANBUS LEDs. Trailer modules with a bad ground can also trigger fast flash.
• Moisture/condensation: Check housing vents, bulb O-rings, and taillamp-to-bed foam seals. Replace cracked lenses promptly.
• Intermittent DRL or flicker: Halogen trucks may flicker with low-quality LED conversions; add anti-flicker capacitors. On factory LED trims, inoperative DRL often means the assembly needs replacement.
• Corroded connectors at rear bumper: Common on trucks exposed to road salt. Clean, apply dielectric grease, and repair terminals as needed.
• BCM bulb-out warnings: Mismatched current draw after bulb changes can flag errors. Use correct wattage bulbs or CANBUS-compatible LEDs and clear codes if needed.

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