What is the low beam headlight bulb size for a 2003 GMC Sierra 1500 HD?

The 2003 GMC Sierra 1500 HD uses a 9006 LED bulb for the low beam headlights. We recommend upgrading to LED for better visibility.

What is the high beam headlight bulb size for a 2003 GMC Sierra 1500 HD?

The high beam bulb size for the 2003 GMC Sierra 1500 HD is 9005 LED.

Why are my 2003 GMC Sierra 1500 HD headlights dim?

Dim headlights on a 2003 GMC Sierra 1500 HD can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a 9006 LED LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2003 GMC Sierra 1500 HD fog light?

The 2003 GMC Sierra 1500 HD uses a 9145 LED bulb for the fog light position.

Is the 2003 GMC Sierra 1500 HD single or dual beam?

The 2003 GMC Sierra 1500 HD uses a dual bulb headlight system. This means you have separate bulbs for high and low beams.

Can I install LED bulbs on my 2003 GMC Sierra 1500 HD?

Yes, the 2003 GMC Sierra 1500 HD comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a 9006 LED LED conversion kit for the low beams.

Does the 2003 GMC Sierra 1500 HD have fog lights?

Yes, the 2003 GMC Sierra 1500 HD takes a 9145 LED bulb for the fog light position.

Did the 2003 GMC Sierra 1500 HD change headlight bulb sizes from the previous year?

No — the 2003 GMC Sierra 1500 HD uses the same bulb sizes as the 2002 model. This configuration has been consistent across the 2002–2003 generation.

Is the 2003 GMC Sierra 1500 HD the first or last year to use 9006 LED bulbs?

The 2003 GMC Sierra 1500 HD is the last year in the 2002–2003 generation to use the 9006 LED bulb for the low beam headlight.

How do I change the headlight on a 2003 GMC Sierra 1500 HD?

Turn off the vehicle and open the hood. Locate the headlight assembly from behind, remove the dust cover or retaining clip, disconnect the wiring harness, twist the old 9006 LED bulb counter-clockwise to remove it, then insert the new bulb and reassemble. The whole process typically takes 10 to 30 minutes per side depending on accessibility.

Are LED headlights legal for a 2003 GMC Sierra 1500 HD?

LED bulbs used off-road or in auxiliary lights are legal everywhere. For on-road headlight use, legality varies by state. Many states allow LED retrofits as long as the beam pattern meets DOT standards. For the best legal compliance, choose a DOT-approved 9006 LED LED kit that is designed as a direct replacement and produces a proper cutoff pattern without excessive glare.

How much does it cost to replace 2003 GMC Sierra 1500 HD headlights?

A pair of halogen 9006 LED bulbs costs $15 to $40, while LED conversion kits run $25 to $60 per pair. If you have a shop do the work, expect an additional $20 to $50 in labor per bulb. Replacing them yourself at home saves the labor cost and usually takes under 30 minutes.

What is the difference between halogen and LED for a 2003 GMC Sierra 1500 HD?

Halogen bulbs produce a warm yellow light (around 3200K), last 500 to 1000 hours, and draw more power. LED bulbs emit a brighter white light (5000-6000K), last 25,000+ hours, and use less energy. LED upgrades for the 9006 LED position are available as direct plug-and-play replacements.

The 2003 GMC Sierra 1500 HD is the last model year to use this bulb configuration (2002–2003).

Fitment Guaranteed for 2003 GMC Sierra 1500 HD

What Size Bulbs Does a 2003 GMC Sierra 1500 HD Use?

Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.

Installation Difficulty

Easy (Plug and Play)

Est. Replacement Cost

$15 - $40 (Halogen) / $30+ (LED)

What Lighting System Does the 2003 GMC Sierra 1500 HD Have?

Lighting on the 2003 GMC Sierra 1500 HD is managed by a total of 15 bulbs, covering everything from primary headlights to signal indicators. It features an extensive lighting system powered by a dual-bulb halogen configuration using separate 9006 LED low beam and 9005 LED high beam bulbs for precise light distribution.

Can You Put LED Bulbs in a 2003 GMC Sierra 1500 HD?

For a GMC built for the road and trail, LED upgrades provide the high-contrast lighting needed for better obstacle detection. We recommend starting your upgrade with the 9006 LED low beams, as they see the most use. Adding a matching 9005 LED LED kit later will complete the look and ensure consistent lighting performance. Don't forget the 9145 LED fog lights; switching these to LED can dramatically improve your visibility in adverse weather.

2003 GMC Sierra 1500 HD Bulb Size Chart

Position	Bulb Size	Shop
Low Beam	9006 LED	Buy 9006 LED →
High Beam	9005 LED	Buy 9005 LED →
Fog Light	9145 LED	Buy 9145 LED →
Brake Light	921 LED	Buy 921 LED →
Side Marker	194 LED	Buy 194 LED →
Turn Signal Front	3157AK LED	Buy 3157AK LED →
Turn Signal Rear	3157K LED	Buy 3157K LED →
Reverse Light	3157K	Buy 3157K →
Dome Light	211-2 or 578	Buy 211-2 or 578 →
License Plate	194	Buy 194 →
Map Light	578 or 168	Buy 578 or 168 →
Parking Light	3157AK	Buy 3157AK →
Trunk Light	912	Buy 912 →
Daytime Running	3157CK	Buy 3157CK →
Tail Light	3157	Buy 3157 →

How do the 2003 GMC Sierra 1500 HD's bulbs compare to other years?

The 2003 GMC Sierra 1500 HD uses the same bulbs as the 2002 model.

The 2004 model switched to a different bulb configuration.

This bulb configuration covers the 2002–2003 model years. ← 2002 2004 →

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Other Sierra 1500 HD Years

2007 2006 2005 2004 2002 2001

Other Vehicles That Use 9006 LED Bulbs

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