Toyota Tercel high beam and low beam headlight bulbs utilize 9003, 9004, or H4666 bulb sizes depending on model generation. The replacement chart covers 1980 through 1998 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Toyota Tercel headlight specifications span three distinct bulb types across its model years: the 9003, 9004, and two sealed beam formats, H4666 and H6054. Both the 9003 and 9004 are dual-filament halogen bulbs operating on 12V, which allows a single bulb to serve both high and low beam functions within one housing.
The 9003 bulb uses a P43t base and carries a 60W/55W rating, where the higher wattage applies to the high beam filament and the lower to the low beam. The 9004 uses a P29t base with a 65W/45W rating, reflecting a different power distribution between its two filaments. These base types are not interchangeable, as the physical connectors differ between the two standards.
The Toyota Tercel (1997-1998) uses the 9003 bulb for both high and low beam headlights, while model years 1995-1996 use the 9004. Because the 9003 and 9004 share a dual-filament design but differ in base type and wattage, one cannot be substituted for the other without an adapter or socket modification.
From 1988-1994, the Toyota Tercel was produced with two distinct headlamp system configurations: halogen capsule headlamps using the 9004 bulb, and sealed beam headlamps using the H4666 unit. The correct replacement depends entirely on which system the specific vehicle was built with.
The H4666 is a rectangular sealed beam unit, meaning the lens, reflector, and light source are fused into a single assembly. When the light source fails, the entire unit requires replacement rather than just an internal bulb. It operates on 12V and conforms to ANSI standards for the US and Canadian markets.
The H6054 is a 5x7-inch rectangular sealed beam unit, also a non-serviceable assembly requiring full unit replacement upon failure. It was the specified headlight format for the Toyota Tercel across model years 1980-1986, covering both high and low beam positions.
Because the H4666 and H6054 are both sealed beam units operating on 12V and conforming to ANSI standards, their shared form factor within their respective size classes means aftermarket halogen-upgraded sealed beam units are often available as drop-in replacements, provided the size and connector match the original specification.
The 9003 bulb is also cross-referenced with the H4 designation used in international markets, though the ANSI 9003 designation is the applicable standard for US and Canadian fitment as listed in these specifications.