1990 Nissan 240sx Headlights: Options For Restoration And Upgrades

The 1990 Nissan 240SX, particularly the S13 chassis, enjoys a legendary status among tuners, drifters, and car enthusiasts. One area often needing attention due to age, damage, or the desire for improved aesthetics and performance, is the headlights. This article explores the options available for restoring and upgrading the headlights on your 1990 240SX, covering everything from basic restoration to full-blown projector swaps.

Understanding Your Stock Headlights

Before diving into upgrades, it's crucial to understand the original headlight configuration. The 1990 240SX (S13) utilizes a sealed beam headlight system. This means the bulb, reflector, and lens are a single, non-serviceable unit. When the bulb burns out, the entire unit needs replacing. The 240SX uses rectangular sealed beams, a common style for the era, but relatively inefficient compared to modern designs. These headlights typically use an H4656 type bulb.

The drawbacks of sealed beam headlights include lower light output, less focused beams, and difficulty in upgrading to brighter or more modern lighting technologies. Additionally, the plastic lenses can become yellowed, cracked, or hazed over time, significantly reducing light output. This hazing is caused by oxidation of the plastic due to UV exposure and environmental factors.

Restoration Options for Sealed Beams

If you're aiming for a stock appearance or are on a tight budget, restoring your existing sealed beams is an option, albeit a limited one. Restoration primarily focuses on cleaning and polishing the plastic lens.

Headlight Restoration Kits

Numerous headlight restoration kits are available on the market. These kits typically include:

Various grits of sandpaper: Used for removing the outer layer of damaged plastic.
Polishing compound: Used to refine the surface and restore clarity.
UV sealant: Applied to protect the restored lens from future oxidation.

The process generally involves:

Cleaning the headlight lens thoroughly.
Sanding the lens with progressively finer grits of sandpaper (typically starting with 400 grit and working up to 3000 grit).
Applying polishing compound with a buffing pad (often included in the kit) attached to a drill.
Cleaning the lens again.
Applying the UV sealant to protect the restored finish.

Important Considerations:

Follow the instructions in the kit carefully.
Use masking tape to protect the surrounding paint.
Apply even pressure when sanding to avoid creating uneven surfaces.
Regularly clean the sanding pad to prevent it from becoming clogged.
The longevity of the restoration depends on the quality of the sealant and environmental conditions. Re-application of the sealant may be necessary every few months.

DIY Restoration

If you prefer a more hands-on approach, you can assemble your own restoration kit. You'll need sandpaper (400, 800, 1000, 1500, 2000, and 3000 grit), polishing compound (like Meguiar's PlastX), a buffing pad for a drill, and a UV sealant (like 303 Aerospace Protectant). The process is the same as described above.

While restoration can improve the appearance of your headlights, it won't significantly improve light output, as the sealed beam itself is still the limiting factor. Also, severely damaged lenses might not be fully restored.

Upgrading to Aftermarket Headlights

For improved performance and a more modern look, upgrading to aftermarket headlights is a popular choice. Several options exist, ranging from simple H4 conversion kits to full projector setups.

H4 Conversion Kits

These kits replace the sealed beam units with housings that accept H4 bulbs. H4 bulbs are a more modern design, offering better light output and the ability to use higher wattage or LED bulbs. Conversion kits typically include:

Two H4 headlight housings.
Wiring adapters to connect to the factory headlight wiring.
H4 bulbs (though you may choose to upgrade these).

Installation is relatively straightforward, involving removing the sealed beams and installing the new housings. Some minor wiring modifications might be required depending on the kit. It's crucial to ensure the wiring is properly insulated to prevent shorts and fires.

Advantages of H4 Conversion:

Improved light output compared to sealed beams.
Wider range of bulb options (halogen, LED, HID).
Easy installation.
Relatively inexpensive.

Disadvantages of H4 Conversion:

Beam pattern might not be as focused as projector headlights.
Potential for glare if using high-wattage bulbs without proper aiming.

Projector Headlights

Projector headlights use a lens to focus the light into a tight, controlled beam. This results in superior light output, a sharper cutoff line (reducing glare for oncoming traffic), and a more modern appearance. Projector headlights are generally considered the best upgrade option for the 240SX.

There are two main types of projector headlights:

Pre-assembled projector headlights: These are complete headlight units with integrated projectors. They are typically plug-and-play, making installation easier.
Bi-xenon projectors: These are more advanced projectors that use a solenoid to switch between low and high beams using a single bulb. This provides excellent light output for both low and high beams.

Advantages of Projector Headlights:

Superior light output and beam pattern.
Reduced glare for oncoming traffic.
More modern and aggressive appearance.
Ability to use HID or LED bulbs for even greater light output.

Disadvantages of Projector Headlights:

More expensive than H4 conversion kits.
Installation can be more complex, especially with bi-xenon projectors.
Requires proper aiming to avoid blinding oncoming traffic.

HID and LED Bulbs

Once you've upgraded to H4 or projector headlights, you can further enhance the light output by using HID (High-Intensity Discharge) or LED (Light-Emitting Diode) bulbs.

HID Bulbs: These bulbs produce light by creating an arc of electricity between two electrodes in a xenon gas-filled tube. They offer significantly brighter light output than halogen bulbs. However, HID bulbs require a ballast to regulate the voltage, which adds to the cost and complexity of the installation.

LED Bulbs: LED bulbs produce light through a semiconductor diode. They are more energy-efficient than halogen and HID bulbs, have a longer lifespan, and produce less heat. Modern LED headlight bulbs can offer comparable or even superior light output to HID bulbs. They also typically don't require a ballast, simplifying installation.

Important Considerations When Choosing HID or LED Bulbs:

Bulb Type: Ensure the bulb type matches the headlight housing (e.g., H4, H1, etc.).
Color Temperature: Measured in Kelvin (K), color temperature affects the color of the light. Lower Kelvin values (e.g., 3000K) produce a yellow light, while higher Kelvin values (e.g., 6000K) produce a blue-white light. A color temperature between 4300K and 6000K is generally recommended for optimal visibility and aesthetics.
Lumens: Lumens measure the total amount of light produced by the bulb. Higher lumens indicate brighter light output. However, be mindful of glare for oncoming traffic.
Quality: Choose reputable brands to ensure quality, longevity, and proper light output. Cheap bulbs can have poor light output, short lifespan, and can even damage your headlight housings.

Wiring Considerations

When upgrading to higher wattage bulbs (halogen, HID, or LED), it's crucial to check the factory headlight wiring. The factory wiring might not be able to handle the increased current draw, potentially leading to voltage drops, overheating, and even fires.

Upgrading the Headlight Wiring Harness: A common solution is to upgrade to a heavier-gauge headlight wiring harness. These harnesses typically use thicker wires and relays to provide a direct, high-current power supply to the headlights, bypassing the factory wiring. This ensures consistent voltage and prevents damage to the factory wiring.

Always disconnect the battery before working on any electrical components.

Aiming Your Headlights

After installing new headlights or bulbs, it's essential to aim them properly. Improperly aimed headlights can reduce visibility and blind oncoming traffic. The aiming procedure varies depending on the headlight type, but generally involves:

Parking the car on a level surface facing a wall or garage door.
Measuring the height of the headlight centers.
Marking the same height on the wall.
Using a level or headlight aiming tool to adjust the vertical and horizontal alignment of the headlights.

Consult your vehicle's service manual or a professional mechanic for specific aiming instructions.

Conclusion

Restoring or upgrading the headlights on your 1990 Nissan 240SX can significantly improve its appearance and safety. Whether you opt for a simple restoration, an H4 conversion, or a full projector setup, understanding the options and considerations outlined in this article will help you make an informed decision and achieve the desired results. Remember to prioritize safety, proper wiring, and accurate aiming to ensure optimal performance and enjoyment of your upgraded headlights.