Chevrolet C-Series Pickup Back Up Light Bulb Size

Additional Notes

• The 1156 bulb is the most frequently specified back up light bulb for the Chevrolet C-Series Pickup, appearing across the majority of model years from 1975 through 2000.
• The 1156 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W, and is produced to ANSI standards applicable in both the United States and Canada.
• The 3156 is a single-filament wedge bulb in the T25 form factor, rated at 12V and 27W, and is the specified back up light bulb for the 1991 and 1997 model years.
• Because the 3156 uses a wedge base rather than a bayonet base, it is not a direct physical substitute for the 1156 despite both being single-filament 12V bulbs.
• The 2456 is a festoon-style bulb rated at 12V and is specified for the 1990 and 1992 model years. Its festoon form factor differs structurally from both the bayonet and wedge base types used in other years.
• The 199 bulb shares the BA15s bayonet base with the 1156 and carries the same 12V, 21W rating, but the two are distinct ANSI part numbers. The 199 is specified exclusively for the 1976 model year of the Chevrolet C-Series Pickup.
• The 1997 model year represents a notable fitment departure, as it specifies the wedge-base 3156 rather than the bayonet-base 1156 used in the surrounding model years from 1993 through 2000.
• The years 1990 and 1992 each call for the 2456 festoon bulb, while the immediately adjacent years specify the 1156, indicating that the socket type changed across certain production periods.
• Substituting a bulb from a different form factor category, such as using a wedge-base 3156 in a socket designed for a bayonet-base 1156, would result in an incompatible fitment regardless of voltage or wattage similarity.
• All four bulb types specified across these model years conform to ANSI standards recognized in both the United States and Canada.