The Isuzu Stylus front and rear turn signal bulbs both utilize a 1157 bulb size for proper operation. The replacement chart covers vehicle production spanning 1991 to 1993.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 is the sole bulb type listed across all turn signal positions for the Isuzu Stylus, covering both front and rear applications for the 1991-1993 model years.
The 1157 is a dual-filament bulb, meaning it carries two separate filaments within a single envelope, one rated at 21W and one at 5W, allowing it to serve both a bright signaling function and a lower-intensity running or parking function simultaneously.
The 1157 operates on a 12V electrical system, which is standard for passenger vehicles of this era.
The base type of the 1157 is the BAY15d bayonet mount, a two-pin offset bayonet configuration. The offset pin placement is a deliberate design feature that prevents incorrect insertion, as reversing the bulb would swap the two filaments and cause incorrect circuit behavior.
The 1157 conforms to ANSI standards and is recognized across both the United States and Canada, placing it within a widely distributed and standardized specification category.
Because the Isuzu Stylus uses the same 1157 bulb for both the front and rear turn signals across all listed model years, a single bulb type services all four turn signal positions on the vehicle.
The BAY15d base of the 1157 is not interchangeable with single-filament bayonet bases such as the BA15s, which shares a similar physical profile but lacks the second offset pin. Substituting a single-filament bulb in a dual-filament socket would result in incomplete circuit function.