Tresound 3rd Brake Light LED High-Mount Cargo Lamp for Chevy Silverado/GMC Sierra 1999–2006, Chrome Housing Red Lens, Plug-and-Pla

Tresound's LED 3rd brake light is a direct-fit, high-mount cargo lamp engineered to replace the factory third brake light on 1999–2006 Chevy Silverado and GMC Sierra trucks with brighter, waterproof LEDs.

If you drive a Silverado or Sierra Classic from 1999–2006 and want a dependable, plug-and-play upgrade to your high-mount stop lamp, this Tresound unit combines modern LED brightness with OEM-style fitment. It swaps in for part numbers 5978318 and 923240, uses a chrome housing with a red lens, and is built from ABS with a foam-mounted back to keep moisture out. The result is improved visibility, long LED life, and installation that avoids drilling or wire splicing.

How does this brake light improve visibility on the road?

The Tresound LED assembly uses high-intensity LEDs that illuminate faster and brighter than older halogen bulbs, helping other drivers see braking cues more clearly. LEDs offer a crisp red output that maintains brightness over time, reducing the chance of dim or uneven lighting at the rear.

• High-output LEDs for quicker illumination and clearer brake indication
• Even light distribution across the red lens to minimize hot spots
• Longer operational life compared with incandescent halogen bulbs

Is installation difficult — will I need to modify my truck?

Installation is designed to be straightforward: the unit is plug-and-play and fits the original mounting points, so no drilling or major modifications are required. This maintains the factory appearance while simplifying replacement.

• Direct replacement for OE part numbers 5978318 and 923240
• Uses factory wiring harness or simple plug-in connector—no splicing
• Mounts with existing holes and hardware for a secure fit

How durable is the Tresound high-mount lamp in wet or cold climates?

The housing is molded from impact-resistant ABS and features a high-density foam backer to seal the assembly against moisture, keeping rain, snow, and road spray from entering the lamp cavity. Multiple quality-control checks are performed during production to ensure consistent manufacturing and longevity.

• ABS construction resists impacts and UV degradation
• Foam-mounted rear seal prevents water intrusion and condensation
• Factory-quality inspection at several production stages for reliability

Will this unit match my truck's appearance and fit OEM expectations?

Yes — the chrome housing and red lens are styled to blend with the original high-mount stop lamp while providing the modern look of LEDs. The shape, mounting pattern, and light output are engineered to align with OEM specifications for the listed model years.

• OEM-style chrome finish and red lens for seamless visual integration
• Exact-fit dimensions for Silverado/Sierra Classic 1999–2006 models
• Designed to meet fitment and functional expectations of the original part

Who is this for? If you own a Chevy Silverado or GMC Sierra 1500/2500/3500 HD Classic from 1999–2006 and you want a reliable, brighter replacement for the factory third brake light without cutting or drilling, the Tresound LED high-mount lamp is made for you. It's suited for owners seeking improved rear signaling, a weather-resistant upgrade for daily drivers, fleet vehicles, or restoration projects where maintaining original fitment is important.