The Isuzu FSR front turn signal requires a 1157 bulb size while the rear turn signal uses a 1156 bulb size. The replacement chart covers vehicle production spanning 1996 to 2002.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu FSR Tilt Cab uses two distinct bulb types across its front and rear turn signal positions for the 1996-2002 model years.
The front turn signal on the Isuzu FSR Tilt Cab takes a 1157 bulb across all 1996-2002 model years.
The 1157 is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d base features two offset pins, which physically prevents it from being seated in a single-filament socket, making cross-position installation between front and rear turn signals impossible.
The rear turn signal uses a 1156 bulb across all 1996-2002 model years, which is a single-filament type rated at 12V and 21W, mounted on a BA15s bayonet base.
The BA15s base carries a single pin and is not interchangeable with the BAY15d base used by the 1157, despite both bulbs sharing the same general bayonet form factor.
Both the 1157 and 1156 are ANSI-standardized bulb types recognized across the United States and Canada, meaning replacements are widely available under those designations.
Although the 1157 and 1156 share the same 21W output on their primary filaments, the 1157 adds a 5W filament that serves a secondary function, a capability the single-filament 1156 does not provide.
The Tilt Cab body style designation applies to every model year entry in these specifications, indicating that all listed fitments are specific to that cab configuration.