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2020 GMC Sierra 2500 HD Bulb Size Chart

Bulb sizes may vary by trim, factory lighting package, region, production date, and previous modifications. Verify the bulb number on your existing bulb before buying.

Last database update: May 2026. Manual review status: Not yet manually reviewed.

Fitment data needs verification

This page is available for browsing, but it is marked noindex until the core bulb data is complete and unresolved manual-review findings are cleared.

Verify before buying: check the bulb number printed on your existing bulb, confirm your trim and factory lighting package, and review the seller's fitment notes.
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2020 GMC Sierra 2500 HD Bulb Size Chart

PositionBulb CodeAliasesTrim / PackageFactory TypeConfidenceReviewNotesShop
Turn Signal Front7443—Standard listingHalogenHigh
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon
Turn Signal Rear7443—Standard listingHalogenHigh
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon
Tail Light7443—Standard listingHalogenHigh
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon
Side Marker194—Standard listingHalogenMedium
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon
Reverse Light921—Standard listingHalogenMedium
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon
Brake Light921—Standard listingHalogenHigh
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon
Parking Light7443—Standard listingHalogenMedium
Pending

Verify trim, factory lighting package, and the bulb number on the existing bulb.

Amazon

2020 GMC Sierra 2500 HD Fitment Notes

Across the 2001-2020 production range, our database shows changes in the listed Turn Signal Front, Turn Signal Rear, Tail Light positions. Use the chart above for this 2020 model, then confirm the bulb number in your vehicle before buying.

Known fitment limitations

  • factory HID or LED packages may use different parts
  • fog lights may depend on equipment package
  • aftermarket headlight assemblies may use different bulbs
  • regional models and production-date splits may differ

See an incorrect bulb size? Submit a correction.

How do the 2020 GMC Sierra 2500 HD's bulbs compare to other years?

The 2020 GMC Sierra 2500 HD changed bulb sizes from 2019. The previous model year used a different configuration.

This bulb configuration covers the 2020 model years. ← 2019

Finding the best installation guide...

Other Sierra 2500 HD Years

2019201820172016201520142013201220112010200920082007200620052004200320022001

More from GMC

10010001000 Series15015001500 Series2502500

Frequently Asked Questions

Our database lists N/A for the 2020 GMC Sierra 2500 HD low beam headlights. Verify the bulb number on your existing bulb and confirm your trim or factory lighting package before buying.

Our database lists N/A for the 2020 GMC Sierra 2500 HD high beam position. Some vehicles vary by trim, lighting package, or previous housing changes.

Dim headlights on a 2020 GMC Sierra 2500 HD can come from aging halogen bulbs, cloudy lenses, weak electrical connections, or an incorrect bulb. Confirm the listed N/A size against the bulb in the housing before choosing a replacement or upgrade.

The 2020 GMC Sierra 2500 HD does not have a fog light bulb listed in our current database. If your vehicle has fog lights, verify the bulb in the housing or owner's manual before buying.

The 2020 GMC Sierra 2500 HD uses a dual bulb headlight system. This means you have separate bulbs for high and low beams.

LED upgrades are available for many N/A applications, but fitment, beam pattern, dashboard warnings, and road-use legality can vary. Use products that list your exact bulb family, such as N, and verify the factory housing before buying.

Yes — the 2020 GMC Sierra 2500 HD uses different bulb sizes than the 2019 model. The 2020 generation introduced this bulb configuration.

The 2020 GMC Sierra 2500 HD is the only year in the 2020 generation to use the N/A bulb for the low beam headlight.

Access varies by engine bay layout and headlight housing. Before disassembly, confirm the listed N/A low beam size on the existing bulb or owner's manual, then follow the service procedure for your exact trim.

Rules for LED headlight retrofits vary by location and by housing type. Avoid products that create glare or lack road-use compliance claims, and check local requirements before using an LED conversion on public roads.

Replacement cost depends on bulb technology, brand, and labor access. Common halogen N/A replacements are usually cheaper than LED conversion kits. Check seller fitment notes before comparing prices.

Halogen bulbs and LED replacements differ in output, heat behavior, beam pattern, and electronics. A correct bulb code does not guarantee a correct LED beam pattern, so verify physical fit and seller compatibility notes for the 2020 GMC Sierra 2500 HD.