Ford Galaxie Back Up Light Bulb Size

The Ford Galaxie back up light uses 1156 and P21W bulb sizes for the rear illumination system. Data for the specific lighting components covers the period from 1959 to 1967.

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
1959-1967	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The 1156 is the sole back up light bulb size listed for the Ford Galaxie across all model years in these specifications, covering 1959-1967.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical characteristics conform to a defined North American standard recognized in both the United States and Canada.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive reverse lighting applications of that era.
The 1156 uses a BA15s bayonet base, a single-contact mount where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d variant with which it is not interchangeable.
The 1156 is a single-filament bulb, meaning it serves only one lighting function, as opposed to dual-filament types that handle two functions such as braking and running light within one housing.
Because the BA15s base relies on a single contact pin, substituting a dual-pin bayonet bulb in the Ford Galaxie's back up light socket would result in an improper fit.