Chevrolet Blazer Cornering Bulb Size

Additional Notes

• The Chevrolet Blazer cornering bulb specifications reference three distinct ANSI-standard bulb types across the listed model years: the 921, the 2456, and the 3156, each carrying different physical forms and electrical ratings.
• The 921 is a T15 wedge bulb rated at 12V and 16W. The wedge base design means the bulb is held in place by tension from the socket rather than by a bayonet or screw mechanism.
• The 3156 is a T25 single-filament wedge bulb rated at 12V and 27W. Its wattage is notably higher than the 921, which reflects a greater light output suited to cornering illumination demands.
• The 2456 is a festoon-style bulb rated at 12V and is designated for specialty applications. Festoon bulbs are cylindrical in form and mount by contact pressure at each end rather than through a conventional socket base.
• The 1996 Chevrolet Blazer uses the 3156, while the 1995 and 1997 model years both use the 2456. These two bulb types are not interchangeable due to differences in base design, physical form, and wattage.
• The 921 and 3156 are both wedge-base bulbs but belong to different size classes, T15 and T25 respectively, meaning they are not cross-compatible despite sharing the same base style.
• All three bulb types conform to ANSI standards applicable in both the United States and Canada, indicating standardized electrical and physical tolerances across those markets.