Turn-signal bulb size on a Toyota 4Runner isn't universal; it depends on the model year and whether you're replacing the front or rear lamp.
For many owners, the most common front signal bulbs are in the 7440/7443 family, while rear signals often use 3156/3157 or 7443 variants. However, exact sizes vary by generation and market, so verify for your specific vehicle.
How sizes vary by generation
To determine the exact bulb size for your 4Runner, consult the owner's manual, inspect the bulb in the socket, or use a trusted parts database. The sizes below are common but not universal; confirm for your model year and region.
- Front turn signal bulbs on many 5th‑generation 4Runners (2010–present): commonly 7440 or 7443 amber bulbs, depending on the socket and wiring configuration. Verify for your VIN and trim.
- Rear turn signal bulbs: often 3156 or 3157 in older generations, with some 5th‑gen models using 7443 in certain rear assemblies; check the manual or read the imprint on the existing bulb.
Note that some markets or trims may deviate from these patterns. Always confirm before purchasing replacements.
How to verify the exact bulb for your vehicle
Use a step-by-step approach to confirm the correct bulb size for your 4Runner.
- Check the owner's manual or a Toyota service bulletin for the bulb specification by year/model.
- Remove the turn signal assembly cover and read the bulb imprint or stamping, which often lists the size (for example, 7440, 7443, 3157, etc.).
- Compare the socket type and base (single vs. dual filament) to ensure the replacement fits and functions correctly.
- If in doubt, contact a Toyota dealer or a reputable parts retailer with your VIN to confirm compatibility.
Following these steps minimizes the risk of buying the wrong part or triggering electrical issues.
LED replacements and cautions
Many owners opt for LED equivalents for longer life and brighter output. LED bulbs are sold as 7440/7443 or 3156/3157 equivalents, but may require CAN‑bus adapters or resistors to prevent hyper-flash on some vehicles. Check compatibility with your system before installation.
When upgrading to LEDs, ensure correct polarity (for some LED variants) and consider the vehicle's electrical loop to avoid issues with the turn signal timing.
Summary
The precise bulb size for a Toyota 4Runner's turn signal depends on year and position. Front signals typically use 7440/7443 variants, while rear signals often use 3156/3157 or 7443, but always verify using the owner's manual, the bulb itself, or a trusted parts database with your VIN. Accurate identification helps ensure proper fitment and safe operation.