Ferrari 348 TB Back Up Light Bulb Size

The Ferrari 348 TB back up light requires 1156 and P21W bulb sizes according to the provided data. The information covers the specific range from 1990 to 1992.

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
1990-1992	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 bulb type listed for the Ferrari 348 TB backup light across the 1990-1992 model years.
The 1156 is an ANSI-standardized bulb recognized in the United States and Canada, operating at 12 volts and 21 watts.
As a single-filament bulb, the 1156 serves one lighting function per unit, which aligns with its dedicated use in a backup light application.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin offset, distinguishing it from dual-contact bayonet variants that are not interchangeable with it.
The BA15s base type is a critical fitment detail, as visually similar bulbs with a BA15d dual-contact base will not seat or function correctly in a socket designed for the 1156.