Key Takeaways

• Bulb Compatibility: The 2002 Pontiac Bonneville utilizes 9005 (HB3) bulbs for high beams and 9006 (HB4) bulbs for low beams.
• Common Failure Points: Owners frequently encounter lens oxidation (yellowing), internal reflector hazing, and moisture condensation.
• Upgrade Path: While OEM halogen is standard, LED conversion kits are popular for increased luminosity, provided they are properly aimed to avoid glare.
• Installation Difficulty: Bulb replacement is rated as easy (15-30 minutes), but full assembly replacement may require bumper fascia removal.

Why Are My 2002 Bonneville Headlights Failing?

Owners of the eighth-generation Pontiac Bonneville often face visibility issues as the vehicle ages. Understanding the root cause is the first step toward a solution.

Lens Oxidation and Yellowing

UV exposure degrades the polycarbonate plastic of the headlight lens over time. This creates a cloudy barrier that significantly reduces light output, even if the bulb is functional. This is the most common complaint among Bonneville drivers.

Internal Reflector Hazing

Unlike lens oxidation, this occurs inside the assembly. The chrome plating on the reflector bowl peels or dulls due to heat cycles. If cleaning the lens does not improve brightness, the entire headlight assembly likely needs replacement.

Electrical and Socket Issues

Intermittent flickering or one-sided failure often points to a corroded bulb socket or a failing ground wire. The GM 9005/9006 connectors can become brittle with age, leading to poor electrical contact.

What Are the Best Replacement Options?

Choosing the right lighting technology depends on your budget, local laws, and desired visibility. Below is a breakdown of the available technologies for the 2002 Bonneville platform.