Nilight LED Third Brake Light for Chevy GMC Silverado Sierra 1999-2006 HD Classic — 18-LED, IP67 Sealed Replacement

Nilight's LED third brake light is a direct-fit replacement designed for select Chevrolet and GMC Silverado/Sierra models (1999–2007 HD Classic) that delivers brighter, faster illumination and reliable all-weather performance.

If you drive a Silverado or Sierra from the late 1990s through the 2007 HD Classic model year, this Nilight third brake light is engineered to match factory mounting points while upgrading the bulb type to long-lived LEDs. It replaces OEM part numbers 5978318 and 923240 and fits a wide range of 1500, 2500 and 3500 model variants, including HD and Classic where specified. Built from OE-grade materials and populated with 18 dedicated LEDs, the assembly gives you quicker response times, greater visibility, and a sealed housing to stand up to seasonal road conditions.

Will this third brake light fit my Chevy or GMC truck?

The Nilight lamp is made to fit specified Chevrolet Silverado and GMC Sierra models from 1999–2006 and certain 2007 HD Classic trucks. Confirm your year and model against the compatibility list before ordering to ensure a direct replacement without modification.

• Compatible: 1999–2006 Silverado/Sierra 1500, 2500, 3500
• Also fits: 2001–2006 1500HD/2500HD/3500HD
• 2007 compatibility limited to the HD Classic model only
• Replaces OEM part numbers 5978318 and 923240

How is the LED version better than the original halogen light?

Compared with OEM halogen bulbs, the Nilight LED array lights faster and emits noticeably more lumens, helping other drivers perceive braking sooner. LEDs are also more energy-efficient and have a longer service life, reducing replacement frequency.

• 18 built-in LEDs: 8 brake + 10 cargo light diodes
• Up to ten times brighter than typical halogen assemblies
• Faster illumination speed to improve reaction time behind your truck

Is the light weatherproof and durable for daily use?

The housing is sealed with a high-density foam pad and constructed to OEM standards to keep moisture and debris out. Nilight recommends applying a butyl sealant after installation to ensure a watertight seal for long-term use in rain, snow, or road wash.

• IP67 waterproof rating when properly sealed
• High-density foam pad included for initial sealing
• OE-grade materials resist vibration and temperature changes

How simple is installation—do I need special tools?

Installation is plug-and-play using the truck’s factory wiring and screws; no drilling required for compatible models. Use the original factory screws and hand tools for the best fit—power tools can overtighten and risk cracking the housing.

• Uses factory mounting points and wiring harness
• Includes one LED third brake lamp and one foam sealing pad
• Recommended: hand screwdriver and butyl sealant for final waterproofing

Who is this for: This Nilight LED third brake light is aimed at Silverado and Sierra owners who want a simple, OEM-style upgrade to brighter, longer-lasting LEDs without modifying the truck. It's ideal for drivers who need increased rear visibility, a direct-fit replacement for worn or damaged third brake lights, or an IP67-rated option built to withstand wet and winter conditions. Always verify vehicle year and model compatibility before purchasing.