Chevrolet K-Series Pickup Back Up Light Bulb Size

Chevrolet K-Series Pickup back up light bulb sizes include 1156, 3156, and 2356 configurations across different model generations. The replacement chart covers vehicle production years spanning 1975 to 2000.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1998-2000	1156
1997	3156
1994-1996	1156
1993	3156
1992	2356
1991	2456
1990	3156
1988-1989	1156
1979-1986	1156
1978	199
1977	1156
1976	199
1975	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament wedge bulb (T25). 12V, 27W.	3156
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V.	2356
ANSI standard (US & Canada). Festoon bulb, specialty application. 12V.	2456
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	199

Other Locations

Additional Notes

The 1156 is the most frequently specified back up light bulb across the Chevrolet K-Series Pickup model years listed, appearing in the majority of entries spanning 1975 through 2000.
The 1156 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W, and conforms to ANSI standards applicable in both the United States and Canada.
The 3156 is a single-filament wedge bulb in a T25 form factor, also rated at 12V but at a higher 27W output than the 1156, and it appears in the 1990, 1993, and 1997 model years.
The 199 bulb shares the same BA15s bayonet base, 12V rating, and 21W output as the 1156 and is classified as a variant of it, though the two carry distinct ANSI designations and are not necessarily interchangeable without verification.
The 199 bulb is specified for the 1976 and 1978 model years, making those years distinct from the surrounding entries that use the 1156.
The 1992 model year is specified with the 2356, a dual-filament bulb with a BAY15d bayonet base rated at 12V. Its dual-filament design and BAY15d base make it physically and electrically incompatible with single-filament BA15s sockets.
The 1991 model year uses the 2456, a festoon-style bulb rated at 12V, which represents a physically distinct form factor from all other bulb types listed across these specifications.
Because the K-Series Pickup uses at least five different bulb types across its listed model years, year-specific confirmation is necessary before substitution, as base types, filament counts, and wattage ratings vary across entries.
The 3156 wedge base and the BA15s bayonet base of the 1156 are mechanically incompatible, meaning the 1997 and 1990 model years require a different socket configuration than the years specified with the 1156.
All bulb types listed across these specifications conform to ANSI standards recognized in both the United States and Canada, indicating a standardized electrical and photometric classification system governs their ratings.