Ford Club Back Up Light Bulb Size

The Ford Club back up light bulb uses either 1141 or 1129 size bulbs as specified in the replacement chart. The chart covers vehicle production years spanning 1953 to 1957.

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
1956-1957	1141
1953-1955	1129

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1141
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1129

Other Locations

Additional Notes

The Ford Club backup light specifications span model years 1953-1957, with two distinct bulb types used across that range.
The 1141 bulb is an ANSI-standard single-filament type rated at 12V and 21W, fitted with a BA15s bayonet base. The BA15s designation indicates a single-contact bayonet cap with a 15mm base width.
The 1129 bulb is an ANSI-standard dual-filament type rated at 12V with a split wattage of 21W and 5W, fitted with a BAY15d bayonet base. The BAY15d base features offset pins that prevent incorrect insertion.
The Ford Club (1956-1957) uses the 1141 single-filament bulb for the backup light position.
The 1953-1955 model years use the 1129 dual-filament bulb for the same position.
The 1129 is noted as a variant of the 1157 bulb. While both share the BAY15d base and dual-filament design, they are not identical, and substitution between them warrants attention to wattage ratings.
The transition from the 1129 to the 1141 between the 1955 and 1956 model years represents a shift from a dual-filament to a single-filament configuration in the backup light circuit.
The BA15s base of the 1141 and the BAY15d base of the 1129 are physically incompatible with each other, meaning the two bulb types are not interchangeable despite both using bayonet-style mounts.