Mazda Protege Back Up Light Bulb Size

The Mazda Protege back up light utilizes 7440, 3497, 1156, and P21W bulb sizes depending on the specific version of the vehicle. Data for the provided components covers a range from 1990 through 2003.

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
1999-2003	7440
1997-1998	3497
1990-1996	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	3497
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Mazda Protege backup light bulb specifications span model years 1990 through 2003, with three distinct bulb types used across that range: the 7440, 3497, and 1156.
All three bulb types share the same electrical ratings of 12 volts and 21 watts, and all are single-filament designs operating under ANSI standards applicable to the US and Canadian markets.
The 1156 is the most frequently specified bulb in the Mazda Protege backup light application, covering model years 1990-1996. It uses a BA15s bayonet base, which is a single-contact base with a 15mm collar.
The 3497 was specified for the 1997-1998 model years. It shares the BA15s bayonet base and identical 12V, 21W electrical characteristics with the 1156, as it is classified as a variant of that bulb type.
Despite the close relationship between the 3497 and 1156, they are listed as separate ANSI designations, and substitution between them should be confirmed against fitment requirements before use.
The 7440 was specified for the 1999-2003 model years. Unlike the 1156 and 3497, it uses a T20 wedge base rather than a bayonet mount, making it physically incompatible with sockets designed for the earlier bulb types.
The transition from a bayonet-base bulb to a wedge-base bulb between the 1998 and 1999 model years reflects a socket change in the vehicle, meaning bulbs from pre-1999 Protege models are not interchangeable with those from 1999-2003 models.