Nissan D21 front turn signal bulbs utilize 1156 or 1157 size specifications, while rear turn signal bulbs require 1156 size. The replacement chart covers 1986 through 1994 production years with corresponding bulb size data.
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 used across North American markets. Despite sharing a 12-volt operating voltage, they serve different electrical functions due to their filament configurations.
The 1156 is a single-filament bulb rated at 21W, fitted with a BA15s bayonet base. Its single-pin base design is specific to single-filament applications and is not interchangeable with dual-filament sockets.
The 1157 is a dual-filament bulb rated at 21W and 5W, fitted with a BAY15d bayonet base. The offset dual-pin base prevents incorrect installation in single-filament sockets, and the two filaments serve separate functions such as turn signaling and running light duties.
The Nissan D21 front turn signal uses either a 1156 or 1157 depending on the model year, meaning the socket type varies across the production run. Installing the wrong bulb type in a mismatched socket is not mechanically possible due to the differing base configurations.
For the 1986-1988 D21, the front turn signal bulb size is determined by the headlamp system installed. Vehicles with sealed beam headlamps take a 1156, while those with halogen capsule headlamps take a 1157.
The rear turn signal position on the Nissan D21 uses the 1156 single-filament bulb across all model years from 1986-1994, indicating a consistent single-filament socket throughout the entire rear turn signal assembly over that span.
In 1989-1990, the front turn signal specifies a 1157, while the rear turn signal specifies a 1156. This means the front and rear turn signal sockets on those model years are not the same type and the bulbs are not interchangeable between positions.
In 1993, the front turn signal specifies a 1157 while the rear specifies a 1156, again reflecting a difference in socket type between the front and rear positions for that year.
In 1991-1992 and 1994, both the front and rear turn signals specify the 1156 bulb, indicating matching single-filament sockets at both positions for those years.
Because the 1156 and 1157 use physically distinct bayonet bases, BA15s and BAY15d respectively, substituting one for the other is not possible without modifying the socket, regardless of their shared voltage rating.