What is the low beam headlight bulb size for a 1999 GMC Sierra 2500-3500?

The 1999 GMC Sierra 2500-3500 uses a 9006 bulb for the low beam headlights. We recommend upgrading to LED for better visibility.

What is the high beam headlight bulb size for a 1999 GMC Sierra 2500-3500?

The high beam bulb size for the 1999 GMC Sierra 2500-3500 is 9005.

Why are my 1999 GMC Sierra 2500-3500 headlights dim?

Dim headlights on a 1999 GMC Sierra 2500-3500 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 conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 1999 GMC Sierra 2500-3500 fog light?

The 1999 GMC Sierra 2500-3500 typically does not come with factory fog lights in all trim levels. If your vehicle is equipped with them, check the manual as sizes can vary by trim.

Is the 1999 GMC Sierra 2500-3500 single or dual beam?

The 1999 GMC Sierra 2500-3500 uses a dual bulb headlight system. This means you have separate bulbs for high and low beams.

Can I install LED bulbs on my 1999 GMC Sierra 2500-3500?

Yes, the 1999 GMC Sierra 2500-3500 comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a 9006 LED conversion kit for the low beams.

How do I change the headlight on a 1999 GMC Sierra 2500-3500?

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 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 1999 GMC Sierra 2500-3500?

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 kit that is designed as a direct replacement and produces a proper cutoff pattern without excessive glare.

How much does it cost to replace 1999 GMC Sierra 2500-3500 headlights?

A pair of halogen 9006 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 1999 GMC Sierra 2500-3500?

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 position are available as direct plug-and-play replacements.

The 1999 GMC Sierra 2500-3500 has a unique bulb configuration not shared with adjacent model years.

Fitment Guaranteed for 1999 GMC Sierra 2500-3500

What Size Bulbs Does a 1999 GMC Sierra 2500-3500 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 1999 GMC Sierra 2500-3500 Have?

Owners of the 1999 GMC Sierra 2500-3500 will find a total of 9 lighting elements throughout the vehicle's exterior. It features a comprehensive lighting system powered by a dual-bulb halogen configuration using separate 9006 low beam and 9005 high beam bulbs for precise light distribution.

Can You Put LED Bulbs in a 1999 GMC Sierra 2500-3500?

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 low beams, as they see the most use. Adding a matching 9005 LED kit later will complete the look and ensure consistent lighting performance.

1999 GMC Sierra 2500-3500 Bulb Size Chart

Position	Bulb Size	Shop
High Beam	9005	Buy 9005 →
Low Beam	9006	Buy 9006 →
Side Marker	194	Buy 194 →
Brake Light	921	Buy 921 →
Turn Signal Rear	3057	Buy 3057 →
Tail Light	3057	Buy 3057 →
Reverse Light	3156	Buy 3156 →
License Plate	194	Buy 194 →
Map Light	168	Buy 168 →

How do the 1999 GMC Sierra 2500-3500's bulbs compare to other years?

The 2014 model switched to a different bulb configuration.

This bulb configuration covers the 1999 model years. 2014 →

Finding the best installation guide...

Other Sierra 2500-3500 Years

2016 2014

Other Vehicles That Use 9006 Bulbs

2017 Mitsubishi Lancer 2016 Chevrolet Express 1500-3500 2015 Chevrolet Express 4500 2014 Dodge Avenger 2014 Mitsubishi Lancer Sedan 2014 Mitsubishi Lancer Sportback

9006 Comparisons

9005 vs 9006 9006 vs H11 9006 vs HB4