Geo Prizm high beam and low beam headlight bulbs utilize 9005, 9004, and 9006 sizes depending on configuration and model year. The replacement chart covers 1989 through 1997 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9004 bulb is a dual-filament halogen type, meaning a single bulb handles both high and low beam functions within one housing. It operates at 12V and carries a dual wattage rating of 65W for high beam and 45W for low beam, with a P29t base.
The Geo Prizm used the 9004 bulb for both high and low beam positions during the 1989-1992 model years, reflecting the dual-filament design that consolidates both functions into one bulb per headlight assembly.
From 1993-1997, the Geo Prizm transitioned to a split-bulb headlight system, with the 9005 assigned to the high beam position and the 9006 to the low beam position. This arrangement uses two separate single-filament bulbs per side rather than one dual-filament unit.
The 9005 is a single-filament halogen bulb rated at 12V and 65W with a P20d base, conforming to the ANSI standard applicable in the US and Canada.
The 9006 is a single-filament halogen bulb rated at 12V and 55W with a P22d base, also conforming to the same ANSI standard. Its lower wattage relative to the 9005 reflects its dedicated low beam role.
The 9005 and 9006 bulbs carry different base types, P20d and P22d respectively, which means they are not physically interchangeable despite their similar single-filament construction and shared voltage rating.
The 9004 base type, P29t, is distinct from both the P20d and P22d bases used by the 9005 and 9006, making the 9004 incompatible with the headlight sockets found on 1993-1997 Prizm models.
All three bulb types in these specifications, the 9004, 9005, and 9006, are halogen bulbs operating on a standard 12V automotive electrical system and comply with ANSI standards recognized in the US and Canada.