Porsche 911 993 Headlights Left Right 99363104100 99363104200

In 2026, the part numbers 99363104100 (Left) and 99363104200 (Right) refer to the original Halogen headlight assemblies for the Porsche 911 (993). These were the standard units for the 1994–1998 Carrera models, manufactured primarily by Bosch.

As the 993 continues to appreciate in value, maintaining the original “glass-look” headlights is essential for preserving the vehicle’s “Investment Grade” status.

1. Technical Identification

• Type: Standard Halogen H1/H1 system.

• Lenses: These feature the iconic fluted glass lenses. In 2026, many owners prefer these over Litronic (Xenon) because they are easier to maintain and don’t require high-voltage ballasts.

• Manufacturer: Bosch (OEM). Look for the Bosch logo embossed on the bottom edge of the glass.

• Fitment: Compatible with all 993 models (Carrera 2/4, RS, Turbo, S, 4S).

3. Common Issues & Solutions

If you are replacing your current 993 headlights, you are likely dealing with one of these “age-related” problems:

• Lens Pitting: Being the most aerodynamic part of the 993, these glass lenses catch road debris. In 2026, you can purchase just the replacement glass and seals if your internal reflectors are still silver and shiny.

• Reflector “Clouding”: The silver coating inside the housing can turn yellow or flake off due to heat. If the reflectors are dull, the light output will be dangerous for night driving.

• Broken Adjustment Tabs: The plastic gears used to aim the headlights become brittle. 99363104100 units include new adjustment mechanisms.

4. Standard Halogen vs. Litronic Upgrade

Many 993 owners ask if they can swap these for the Litronic (Xenon) units (993-631-051-00).

• Direct Fit: They are physically interchangeable.

• Wiring: The Litronic units require an additional wiring harness for the headlight washers and the high-voltage ballast.

• Cost: A pair of new Litronics in 2026 can exceed $5,500, making the standard halogen units a much more cost-effective choice for a driver-quality car.

5. Installation Tip

The 993 features a unique “flick” lever inside the fender to release the entire headlight assembly.

Pro Tip: Before sliding the new units in, apply a light coat of Silicone Grease to the large rubber gasket. This prevents the rubber from binding and ensures a perfect, watertight seal against the paint.