Chrysler Windsor Back Up Light Bulb Size

The Chrysler Windsor back up light bulb size chart specifies 3 distinct bulb options: 1073, 1156, and 1129 for this vehicle model. The replacement chart covers 1951 through 1961 production years with corresponding bulb size specifications.

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
1961	1073
1958-1960	1156
1956-1957	1073
1951-1955	1129

Bulb Specifications

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

Other Locations

Additional Notes

The Chrysler Windsor backup light specifications span model years 1951 through 1961, covering three distinct bulb types across that period.
The 1129 bulb is the most frequently specified type in these records, appearing in the Chrysler Windsor from 1951 through 1955.
The 1129 is a dual-filament bulb rated at 12V and 21/5W, using a BAY15d bayonet base, which features offset pins to prevent incorrect installation.
As a variant of the 1157, the 1129 shares the same BAY15d base but carries different wattage or electrical characteristics, meaning the two are not directly interchangeable despite their physical similarities.
The 1156 bulb appears in the Windsor for model years 1958 through 1960, rated at 12V and 21W with a single filament and BA15s bayonet base.
The 1073 bulb is specified for the Chrysler Windsor in 1956, 1957, and 1961, and is described as a lower wattage variant of the 1156, rated at 12V and 13W.
Both the 1073 and 1156 use the same BA15s single-pin bayonet base, which means they are physically compatible in terms of fitment, though their wattage ratings differ significantly.
Substituting a 1156 for a 1073 in years where the lower wattage type is specified would result in a higher current draw than the original circuit was designed to accommodate.
All three bulb types conform to ANSI standards recognized in both the United States and Canada.
The shift from the dual-filament 1129 to single-filament types beginning in 1956 reflects a change in the electrical configuration of the Windsor's backup light circuit across these model years.