Infiniti G37 Headlights: The Ultimate Owner’s Guide to Maintenance, Repairs, and Smart Upgrades

If you drive an Infiniti G37, your headlights are more than just functional—they’re a critical safety feature, a style statement, and a component that can save you money (or cost you dearly) depending on how you care for them. After working with hundreds of G37 owners over the years and diving deep into factory service manuals, aftermarket data, and real-world owner feedback, here’s the no-nonsense truth: Proper maintenance, timely repairs, and informed upgrades are the keys to keeping your G37’s headlights bright, legal, and reliable for years. Ignore them, and you risk reduced visibility on the road, failed inspections, or even costly damage to other components. Let’s break down everything you need to know.

First: Understand Your G37’s Headlight System (Because Not All Years Are Created Equal)

The Infiniti G37 was produced from 2007 to 2013, with minor updates in 2010 and 2012. Headlight technology varied by model year, trim level, and market (U.S. vs. international), so the first step is to confirm exactly what type of headlights your car has.

• 2007–2009 Models: Most came standard with halogen headlights. These use a tungsten filament heated by an electric current to produce light. They’re reliable but dimmer than newer tech—expect 1,000–1,500 lumens per bulb.
• 2010–2013 Models: Infiniti introduced optional Xenon (HID) headlights on the G37 Coupe and Roadster. These use high-voltage arc technology to produce brighter (2,800–3,500 lumens), whiter light. Some base models still used halogens, so check your owner’s manual or look at the bulb housing (HID units have a larger, rectangular shape with a ballast module nearby).
• Key Note: Even within the same year, G37s ordered with the “Premium Package” or “Technology Package” may have upgraded headlights (e.g., auto-leveling, fog lights integrated into the housing). Always verify your setup—mistaking a halogen for HID (or vice versa) during repairs can lead to wasted time and money.

Maintenance 101: Keep Your G37’s Headlights Bright and Safe

Headlights degrade over time—even factory units. The good news? Most issues are preventable with simple, regular care. Here’s your step-by-step maintenance plan.

1. Clean Them… Properly (No, Household Glass Cleaner Isn’t Good Enough)

Dirt, bugs, tree sap, and road grime can cut headlight output by up to 50% in just six months. But scrubbing with Windex or paper towels will scratch the plastic lens over time. Instead:

• Step 1: Rinse the headlights with water to remove loose debris.
• Step 2: Apply a dedicated automotive headlight cleaner (look for formulas with UV inhibitors, like 3M or Meguiar’s). Avoid products with ammonia—they can cloud the plastic.
• Step 3: Gently rub with a soft microfiber cloth or sponge in circular motions. For tough stains (like bug splatter), let the cleaner sit for 2–3 minutes before wiping.
• Step 4: Rinse thoroughly and dry with a clean, lint-free towel.

Pro Tip: Do this every 3 months, or more often if you drive on salted roads in winter.

2. Check the Seals—Before Water Ruins Everything

G37 headlights are sealed to prevent moisture buildup, but rubber gaskets and seals degrade over time. If you notice condensation inside the lens (a common issue in older models), act fast:

• Inspect the Seals: With the hood up, look around the headlight housing edges. Cracks, splits, or hardening (the rubber feels stiff, not flexible) mean it’s time to replace them.
• Replace Seals: You can buy OEM or aftermarket seal kits (e.g., DEPO, TYC) for $15–$30. Use a trim tool to gently pry off the old seal, clean the groove with isopropyl alcohol, and press the new seal into place.
• Sealant Backup: For extra protection, apply a thin bead of automotive silicone sealant (like Permatex Ultra Disc) along the outer edge of the seal. It creates a waterproof barrier without interfering with the original gasket.

3. Replace Bulbs Before They Burn Out (Yes, Even Halogens)

Halogen bulbs last 400–600 hours, but they dim gradually—you might not notice until it’s dangerous. HID bulbs last longer (2,000–3,000 hours) but are pricier. Here’s when to replace:

• Halogen: If the low beam is dim, takes longer to reach full brightness, or casts a yellowish tint, replace both bulbs (even if one still works—mismatched brightness is dangerous and illegal).
• HID: Flickering, inconsistent color (e.g., one side is blueish, the other yellow), or a “humming” noise from the ballast means the bulb or ballast is failing.

How to Replace G37 Headlight Bulbs:

• Turn Off the Car: Let the headlights cool completely (HID bulbs get extremely hot).
• Open the Hood: Locate the headlight assembly—each is held in place by 2–3 screws or clips.
• Remove the Assembly: For halogen models, twist the bulb socket counterclockwise and pull it out. For HID, disconnect the electrical connector first (it’s attached to the ballast; be careful not to tug on the wires).
• Handle New Bulbs with Gloves: Oils from your skin can cause hot spots on the bulb, shortening its life. Use the cloth included with the bulb or nitrile gloves.
• Test Before Reinstalling: Plug the bulb in and turn the headlights on to confirm it works.

Cost Note: OEM halogen bulbs cost $15–$25 each; HID bulbs (D2S or D2R, depending on model) run $50–$80. Aftermarket options are cheaper but vary in quality—stick to brands like Philips, Sylvania, or Osram.

Troubleshooting Common G37 Headlight Issues (And How to Fix Them)

Even with maintenance, problems happen. Here’s how to diagnose and fix the most common complaints.

Issue 1: One Headlight Is Dimmer Than the Other

Likely Causes:

• A dying bulb (even if it hasn’t “burned out” yet).
• A corroded or loose bulb socket (common in older G37s).
• A faulty ground wire (the ground connection sends electricity back to the battery—if it’s corroded, the bulb doesn’t get enough power).

Fixes:

1. Swap the bulbs between the two headlights. If the dimness moves, replace the bad bulb.
2. Inspect the socket for corrosion (white/green buildup). Clean it with electrical contact cleaner and a wire brush.
3. Check the ground wire (usually a black wire connected to the headlight housing). Scrape off rust with sandpaper, apply dielectric grease, and tighten the connection.

Issue 2: Headlights Flicker or Turn Off Intermittently

Likely Causes:

• Loose or damaged wiring (vibrations from driving can wear down wires over time).
• A failing HID ballast (common in 2010+ models—ballasts regulate the high voltage needed for HID bulbs).
• A bad alternator (if flickering happens with other electrical issues, like dimming interior lights).

Fixes:

1. Inspect wiring harnesses near the headlights and engine bay. Look for frayed wires or loose connectors. Repair with heat-shrink tubing or replace damaged sections.
2. Test the ballast: Use a multimeter to check for 12V input. If the input is good but the bulb still flickers, replace the ballast ($100–$150 OEM, $60–$100 aftermarket).
3. Have the alternator tested at an auto parts store (most do free diagnostics). A failing alternator needs replacement ($400–$800).

Issue 3: Headlights Are Cloudy or Yellowed (Even After Cleaning)

Likely Causes:

• UV damage (plastic oxidizes over time, especially if you park in direct sunlight).
• Chemical exposure (road salt, bug spray, or tree sap can degrade the lens coating).

Fixes:

• Polishing: Use a headlight restoration kit (e.g., 3M Headlight Lens Restoration System). These include abrasive pads and polish to remove oxidation. Follow the instructions carefully—you don’t want to scratch the lens.
• Professional Resurfacing: If polishing doesn’t work, a detailer can machine-polish the lens with a rotary buffer. This removes deeper oxidation but costs $100–$200.
• Replacement: If the lens is cracked or severely damaged, replacing the entire headlight assembly is safer. OEM assemblies cost $500–$800 per side; aftermarket (DEPO, TYC) are $200–$400.

Upgrading Your G37’s Headlights: What You Need to Know

Want brighter, modern headlights? Upgrading is popular, but it’s not as simple as swapping bulbs. Here’s how to do it right.

Option 1: Halogen → HID (Xenon) Conversion

Pros: HID bulbs are 2–3x brighter than halogens, with a whiter color (4,300K–6,000K) that improves visibility.
Cons:

• Requires a ballast and igniter (extra cost: $150–$300).
• May not fit in older G37 headlight housings (check clearance—some aftermarket HIDs are too large).
• Illegal in some areas if the light pattern is too wide or blue (check local laws—most U.S. states require DOT-compliant bulbs).

Installation Tips:

• Buy a conversion kit designed for your G37’s headlight type (projector vs. reflector). Reflector housings (older G37s) can cause HID light to scatter, blinding other drivers.
• Use a color temperature of 4,300K–5,000K (higher K numbers are bluer and less effective in fog/rain).

Option 2: HID → LED Upgrade

Pros: LEDs are even brighter, last longer (50,000+ hours), and draw less power than HIDs. They also come in a range of colors (5,000K–6,500K is best for visibility).
Cons:

• Heat management is critical—cheap LEDs can overheat and fail.
• Beam pattern may be uneven (projector housings handle LEDs better than reflectors).
• Legal compliance: Ensure the LED bulbs are ECE/DOT certified (look for “DOT” or “E-mark” on the packaging).

Installation Tips:

• Choose plug-and-play LEDs (no wiring needed) for simplicity. Brands like Morimoto, Diode Dynamics, and Philips X-tremeVision are reliable.
• Test the beam pattern before finalizing—if the light is scattered or too high, return them.

Option 3: Aftermarket Projector Headlights

Pros: Factory projectors are basic—aftermarket units (e.g., DEPO, Seibon) have better lenses and reflectors, producing sharper, more focused beams. They’re also available with HID or LED options.
Cons: Cost ($800–$1,500 per pair) and installation complexity (may require modifying the front bumper).

Installation Tips:

• Measure your G37’s headlight mounting points (distance between brackets, height) to ensure a fit.
• Have a professional install them if you’re not comfortable with bumper modification—they’ll align the beams correctly to avoid blinding other drivers.

When to Call a Professional (And When to Save Money)

Some headlight issues are simple to fix yourself, but others require expertise. Here’s the breakdown:

• DIY Safe: Bulb replacement, cleaning, seal checks, minor wiring repairs.
• Call a Pro:
  • Ballast or HID igniter failure (incorrect installation can damage the car’s electrical system).
  • Severe oxidation or cracked lenses (professional polishing ensures even results).
  • Legal upgrades (a mechanic can verify compliance with local regulations).

Red Flag: Avoid “headlight restoration” services that use harsh chemicals or aggressive sanding—they can weaken the plastic over time. Stick to reputable detailers or do it yourself with a quality kit.

Final Thoughts: Your G37’s Headlights Deserve Care (And So Do You)

Your Infiniti G37’s headlights are a small part of the car, but they play a huge role in safety, performance, and even resale value. By following this guide—staying on top of maintenance, troubleshooting issues early, and upgrading wisely—you’ll keep your headlights shining bright for years. Remember: A little time and money now can save you from a dangerous situation (or a costly repair) later. Now get out there, drive safely, and let your G37’s headlights light the way.