Nissan 240SX front turn signal bulbs use 1156 or 1157 size, while rear turn signal bulbs use 1156 size. The replacement chart covers 1989 to 1998 model 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 1156 and 1157 are both ANSI-standardized bulb types recognized across the United States and Canada, meaning they conform to a shared set of electrical and physical standards within those markets.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base. The single filament means it serves one lighting function per socket.
The 1157 is a dual-filament bulb rated at 12V with two wattage outputs of 21W and 5W, fitted with a BAY15d bayonet base. The two filaments allow it to serve two lighting functions, such as turn signaling and running light operation, within a single socket.
The BA15s base of the 1156 and the BAY15d base of the 1157 are physically distinct. The BAY15d base has offset locating pins, while the BA15s base has a single-contact, centered pin arrangement. These two bases are not interchangeable.
For the Nissan 240SX, the front turn signal position uses the 1157 bulb for model years 1989-1994 and transitions to the 1156 bulb for model years 1995-1998.
The rear turn signal position on the Nissan 240SX uses the 1156 bulb across all model years from 1989-1998, with no variation throughout the production run covered by these specifications.
Because the front turn signal socket changed from a dual-filament 1157 to a single-filament 1156 at the 1995 model year, the socket wiring configuration differs between the earlier and later generations of the 240SX front turn signal housing.
Installing a 1156 in a socket designed for a 1157 is not a direct substitution, as the base pin configurations differ and the socket would not accommodate the alternate base without modification.