Ferrari 348 TB front and rear turn signal bulbs utilize a 1156 size bulb for both applications. The replacement chart covers 1990 to 1992 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Ferrari 348 TB uses the 1156 bulb type across both its front and rear turn signal positions for the 1990-1992 model years.
The 1156 is a single-filament bulb, meaning it is dedicated to one lighting function rather than sharing a filament with another, such as braking or running lights.
It operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard incandescent automotive turn signal applications.
The 1156 uses a BA15s bayonet base, a single-contact fitting where the bulb locks into the socket with a twist. The "s" in BA15s denotes a single contact point at the base, distinguishing it from the dual-contact BA15d variant.
Because the Ferrari 348 TB uses the same 1156 bulb in all four turn signal positions, front and rear, a single bulb type covers the full turn signal circuit of the vehicle.
The 1156 is an ANSI-standardized bulb recognized across the United States and Canada, meaning its physical and electrical specifications conform to a defined industry standard rather than a proprietary format.
The BA15s bayonet base is not interchangeable with the BA15d base. Substituting a dual-contact bulb in a single-contact socket would result in an improper fit.