Dodge Royal Back Up Light Bulb Size

The Dodge Royal back up light uses bulb size 1073 or 1129 depending on the specific version of the vehicle. Available information covers the range from 1954 to 1959.

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
1956-1959	1073
1954-1955	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). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1129

Other Locations

Additional Notes

The Dodge Royal back up light specifications cover the 1954-1959 model years, with two distinct bulb types used across that range.
The 1073 bulb is an ANSI-standardized single-filament bulb operating at 12 volts and 13 watts, fitted with a BA15s bayonet base.
The BA15s base on the 1073 is a single-contact bayonet mount, which is not interchangeable with dual-contact bayonet bases.
The 1073 is a lower-wattage variant of the 1156 bulb, sharing the same BA15s base type but differing in wattage output.
The Dodge Royal (1956-1959) uses the 1073 bulb for the back up light position across all four of those model years.
The 1129 bulb is an ANSI-standardized dual-filament bulb operating at 12 volts with a 21/5W rating, fitted with a BAY15d bayonet base.
The BAY15d base on the 1129 is an offset dual-contact bayonet mount, designed to prevent incorrect bulb orientation during installation.
The 1129 is a variant of the 1157 bulb and shares its dual-filament configuration, with the two wattage values corresponding to its two separate filaments.
The Dodge Royal (1954-1955) uses the 1129 bulb for the back up light position.
The 1073 and 1129 bulbs use physically different base types, BA15s and BAY15d respectively, making them non-interchangeable with each other.