Plymouth Savoy Back Up Light Bulb Size

The Plymouth Savoy back up light utilizes bulb sizes 1129, 1073, 1141, and P21W depending on the specific version of the vehicle. Data for the bulb requirements covers the range from 1953 to 1964.

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
1963-1964	P21W
1962	1141
1959-1961	P21W
1956-1958	1073
1953-1955	1129

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1141
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.	1129

Other Locations

Additional Notes

The Plymouth Savoy back up light specifications span model years 1953 through 1964, covering four distinct bulb types across that period.
The P21W is the most frequently specified bulb in these records, covering the 1959-1964 model years with the exception of 1962. It follows the ECE standard and operates at 12V, 21W with a single filament and BA15s bayonet base.
The 1141 bulb is specified exclusively for the 1962 Plymouth Savoy. Although it shares the ANSI standard designation rather than the ECE classification of the P21W, both bulbs are electrically identical at 12V and 21W and use the same BA15s bayonet base.
Because the P21W and the 1141 share the same base type and identical voltage and wattage ratings, they are functionally interchangeable in practice, though they originate from different standardization systems.
The 1073 bulb is specified for the 1956-1958 model years. It is an ANSI-standard single-filament bulb with a BA15s bayonet base, rated at 12V and 13W, making it a lower-output unit than either the P21W or the 1141.
The 1073 is described as a lower wattage variant of the 1156 bulb. While it shares the same BA15s base as the 1156, the reduced wattage means the two are not drop-in replacements for one another without accounting for the output difference.
The 1129 bulb is specified for the 1953-1955 Plymouth Savoy. Unlike every other bulb in these specifications, the 1129 is a dual-filament type rated at 12V with a 21W and 5W filament configuration.
The 1129 uses a BAY15d bayonet base, which is physically distinct from the BA15s base found on the P21W, 1141, and 1073. The offset pins of the BAY15d base prevent accidental installation of a single-filament bulb in a socket designed for dual-filament use.
The 1129 is noted as a variant of the 1157. The shared base type and dual-filament design place both in the same family, though specific electrical characteristics may differ between the two designations.
A base-type change occurs between the 1955 and 1956 model years, where the Plymouth Savoy transitions from the BAY15d dual-filament socket of the 1129 to the BA15s single-filament socket of the 1073, reflecting a change in the back up light circuit design.