Toyota 4Runner Brake Bulb Size

Additional Notes

• The Toyota 4Runner brake bulb specifications cover three distinct bulb types across the listed model years: the 7443, 1157, and 1034 for standard brake positions, and the 921 for the Center High Mount Stop Light.
• The 7443 is a dual-filament wedge bulb in the T20 form factor, rated at 12V with a 21W high-intensity filament and a 5W running filament, conforming to ANSI standards for the US and Canadian markets.
• The 1157 shares the same 12V, 21W/5W dual-filament output as the 7443 but uses a BAY15d bayonet base rather than a wedge-style connection, making the two bulbs electrically similar yet physically incompatible without an adapter.
• The 1034 is a BAY15d bayonet-base dual-filament bulb and a variant of the 1157, also rated at 12V, 21W/5W. Despite the shared base type and wattage, the 1034 and 1157 are distinct ANSI designations and are not directly interchangeable.
• The 921 is a single-filament T15 wedge bulb rated at 12V, 16W, and is used exclusively in the Center High Mount Stop Light position. Its single-filament design reflects the dedicated on/off function of a high-mount stop light, which requires no separate running-light filament.
• The Toyota 4Runner (1996-2013) uses the 7443 wedge bulb for standard brake lighting, representing the most widely specified bulb across the listed model years in these specifications.
• The Outer Brake sub-part for the 1996 model year carries a production date qualifier of "From 11/1995," indicating that the 7443 fitment applies only to units produced from that date onward within the model year, while the 1995 model year in the same sub-part specifies the 1157.
• Similarly, the 2013 Outer Brake entry is qualified as "To 08/2013," and the 2005 and 2000 entries carry equivalent mid-year cutoffs, indicating that bulb fitment within a single model year can vary depending on production date.
• The Center High Mount Stop Light specifications cover model years 1993-2009, with the 921 bulb specified uniformly across all listed years in that position.
• The standard brake position for model years 1984-1989 specifies the 1034, while 1990-1995 specifies the 1157. Both use the BAY15d bayonet base, but substituting one for the other is not supported by these specifications due to their distinct ANSI designations.