Chrysler Imperial Back Up Light Bulb Size

The Chrysler Imperial back up light utilizes 3157, 2458, 1156, 1073, 1142, 1129, and P21W bulb sizes depending on the specific production period. Available technical data for the lighting components spans from 1951 through 1993.

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
1990-1993	3157
1981-1983	1156
1966-1975	1156
1965	1073
1963-1964	1142
1962	1156
1961	1073
1959-1960	1156
1957-1958	1073
1951-1955	1129

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	1073
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1142
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1129

Other Locations

Additional Notes

The Chrysler Imperial back up light specifications cover model years 1951 through 1993, with two distinct bulb types accounting for the majority of fitments across that span: the 1156 and the 3157.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base. It is the most frequently specified bulb across the Chrysler Imperial back up light data, appearing in model years 1959-1960, 1962, and 1966-1983.
The 3157 is a dual-filament wedge bulb in a T25 form factor, rated at 12V with a 27W main filament and a 7W secondary filament. It is specified for the 1990-1993 model years. Because it carries two filaments, it is not a direct substitute for single-filament types such as the 1156.
The 1073 shares the same BA15s bayonet base as the 1156 but operates at a lower wattage of 13W. Despite the identical base type, the reduced wattage means the two bulbs are not electrically equivalent, and substituting one for the other may affect output brightness.
The 1142 and 1129 are both dual-filament bulbs rated at 12V and 21/5W, each using a BAY15d bayonet base. The BAY15d base is offset-pin, which physically prevents installation in a BA15s socket, making these bulbs incompatible with sockets designed for the 1156 or 1073.
The 1129 is specified for the Chrysler Imperial in model years 1951-1952 and 1953-1955, representing the earliest fitments in the dataset.
The 1142 is specified only for the 1963-1964 model years, making it the least frequently appearing bulb type in these specifications.
The 1073 is specified for the 1957-1958, 1961, and 1965 model years. Its lower wattage relative to the 1156 reflects a deliberate engineering choice for those specific model years rather than a general interchangeability with the higher-wattage single-filament type.
All bulb types listed in these specifications conform to ANSI standards applicable in the United States and Canada, indicating standardized dimensional and electrical tolerances across the range.
The shift from single-filament BA15s and BAY15d bayonet-base bulbs in earlier model years to the dual-filament T25 wedge format of the 3157 in the 1990-1993 model years reflects a change in socket and housing design, meaning earlier and later model year components are not interchangeable.