The LS400 uses standard 12V automotive bulbs, but exact types vary by year and market. Headlights are typically a dual-beam setup (often listed as H4/9003/HB2), with separate options in some regions; other bulb types include H11 for fog lights, wedge bulbs such as 194/168 for parking and interior lights, and 1156/1157 or 7440/7443 style bulbs for turn signals.
Headlights
The exact headlight bulb can vary by year and market. Here are common possibilities you may encounter when replacing LS400 headlamps.
- H4 dual-filament (also marketed as 9003/HB2 in some catalogs): a single bulb that provides both low and high beams in many LS400 configurations.
- Separate low/high-beam setup (less common in some markets): 9006 (low beam) and 9005 (high beam) in two-bulb arrangements.
Because headlight assemblies and connectors changed over the years and by region, the best approach is to check the bulb currently installed or confirm with the owner's manual or Lexus parts diagram for your exact year/model. If you’re retrofitting with brighter bulbs, ensure any replacements are compatible with the housing and wiring.
Fog lights
Not all LS400s came with factory fog lights, and installations can differ by market. If your car has fog lamps, they typically use a standard 12V halogen bulb in the H11 family.
- Fog lamp bulb: H11
If your LS400 lacks fogs, this section may not apply, but if you’re adding or replacing them, verify the housing and wiring before purchasing bulbs.
Parking lights and corner/marker lamps
Parking and marker lamps use small wedge bulbs, with variations depending on the year and trim level. Common options include:
- Parking/position lights: 194 or 168 wedges
- Corner/side marker lamps: 194 or 168 wedges
Check the lens markings or the vehicle’s service manual to confirm the exact wedge size for your LS400’s year and market.
Turn signals
Front and rear turn signals may use different bulb types depending on the assembly. Typical options include a few common automotive bulbs in the 12V range.
- Front turn signals: commonly 7440 or 7443 variants (some markets may use single-filament 1156/1157 equivalents).
- Rear turn signals: often 7440/7443 variants or other 12V single-filament bulbs depending on the tail/marker assembly.
Since signaling assemblies can differ by year and region, verify by removing the old bulb and reading its base, or consult the Lexus parts catalog for your exact VIN/year.
Interior and instrument panel lights
Interior illumination uses several small wedge bulbs and festoon bulbs in the dash, map lights, and glovebox. Common types you may encounter include:
- Dash and instrument panel: 194 or T5 wedge bulbs (varies by gauge cluster design)
- Map lights and overhead bulbs: small wedge bulbs such as 194/T5
- Glovebox and cargo area lights: 194 or similar wedge types
If you’re replacing multiple interior bulbs, it’s helpful to note the location and check the vehicle’s manual for precise base types and whether LED replacements are supported by the wiring.
License plate lights
Most LS400s use a small wedge or festoon bulb for the license plate lamp. Commonly:
- License plate bulb: 194 or similar 12V wedge
Verify the exact base and length for your year/model if you’re ordering replacements online.
Year and market variations
Because the LS400 existed across several years and markets (US, Japan, Europe) with minor cosmetic and electrical differences, bulb types can vary. When in doubt, use one of these quick checks:
- Compare the bulb base and socket with the replacement part to ensure a match.
- Consult the owner’s manual or the Lexus parts diagram for your exact year and market (these often list bulb sizes explicitly).
- Carefully remove the existing bulb and read the markings on the base for a precise match.
If you need, you can also provide your LS400’s year and market (e.g., US 1990-1994, or 1995-1997 first generation) and I can narrow down the exact bulb part numbers.
How to verify and upgrade
To ensure you’re buying the correct bulbs and maximizing performance, follow these steps:
- Inspect the current bulbs for base type and code markings.
- Check the owner’s manual or a reputable parts catalog for your exact year/model.
- Consider upgrading to high-performance halogen replacements or LED equivalents only if the housing and wiring support them and if beam patterns remain legal in your area.
Handy tip: when replacing bulbs, replace in pairs to maintain consistent brightness and color. Always disconnect the battery before changing electrical bulbs to avoid shorts or injury.
Summary
In short, an LS400 commonly uses H4/9003-style headlamps for many markets, H11 for fogs when equipped, 194/168 wedge bulbs for parking and marker lights, 1156/1157 or 7440/7443 variants for turn signals, and 194/T5 wedges for interior and gauge illumination. Exact bulb types depend on the year and market, so always verify with the owner’s manual or a parts diagram for your specific LS400. If you’d like, tell me the model year and market (US, Europe, Japan) and I’ll provide a precise, year-specific bulb list.
Closing note
Tracking down the exact bulb sizes for an LS400 can be straightforward when you know where to look. Start with the bulb you remove, consult the manuals or parts diagrams for your exact year, and consider sticking with original-equivalent replacements to maintain optimal beam patterns and safety on the road.