Dodge Seneca Back Up Light Bulb Size

The Dodge Seneca back up light bulb size chart specifies 2 bulb sizes: 1073 and 1156. The replacement chart covers vehicle production years from 1960 to 1961.

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
1960	1156

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

Other Locations

Additional Notes

The 1156 bulb is specified for the 1960 Dodge Seneca back up light, while the 1073 is specified for the 1961 model year.
Both the 1073 and 1156 are ANSI-standard single-filament bulbs recognized in the US and Canada, each using a BA15s bayonet base.
The BA15s designation refers to a single-contact bayonet base with a 15mm collar, a common format in automotive lighting applications.
Despite sharing the same base type, the two bulbs differ in wattage: the 1156 operates at 21W, while the 1073 operates at 13W.
Both bulbs operate at 12V, consistent with standard automotive electrical systems.
The 1073 is regarded as a lower-wattage variant of the 1156, meaning the two are not directly interchangeable without accounting for the difference in light output.
The shared BA15s base between the 1073 and 1156 means one can be physically inserted in place of the other, but the wattage difference produces a measurable variation in brightness.