The Isuzu Ascender turn signal requires a 3157NA bulb size for the front or rear lighting components. Data for the specific bulb requirements covers the range from 2003 to 2008.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu Ascender uses the 3757NA bulb for the front turn signal across all model years from 2003-2008.
The 3757NA is a dual-filament wedge bulb rated at 12V, classified under the T25 body type, and carries natural amber glass to produce an amber light output without the use of a colored lens or coating.
As an ANSI-standardized part, the 3757NA meets the same specification recognized in both the United States and Canada.
The rear turn signal on the Ascender uses the 3156NA bulb across all model years from 2003-2008.
The 3156NA is a single-filament wedge bulb rated at 12V and 27W, also housed in a T25 form factor with natural amber glass.
The key distinction between the 3757NA and 3156NA is filament count. The front position requires a dual-filament bulb, while the rear position requires a single-filament bulb. These two types are not interchangeable despite sharing the same T25 body type.
Both bulbs conform to ANSI standards applicable in the United States and Canada, indicating they meet a defined set of electrical and photometric requirements for automotive lighting.
The natural amber glass on both bulb types produces amber light inherently through the glass itself, rather than relying on an external amber lens to filter a clear light source.