The Isuzu NRR uses a 1157 bulb size for front turn signal applications and a 1156 bulb size for rear turn signal functions. A replacement chart covering 2005 through 2013 model years documents the bulb size specifications for this vehicle.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu NRR uses the 1157 bulb for the front turn signal across all Tilt Cab configurations from 2005-2013.
The 1157 is a dual-filament bulb, meaning it serves two lighting functions within a single housing. It operates on a BAY15d bayonet base at 12V, with filaments rated at 21W and 5W respectively.
The BAY15d base features two offset pins, a design that prevents incorrect insertion and distinguishes it physically from single-filament bases.
The rear turn signal on the Isuzu NRR uses the 1156 bulb across all Tilt Cab configurations from 2005-2013.
The 1156 is a single-filament bulb operating on a BA15s bayonet base at 12V and 21W. The BA15s base uses a single pin, which is not interchangeable with the dual-pin BAY15d base used by the 1157.
Although the 1157 and 1156 share a similar physical profile and the same 21W primary filament rating, the differing base configurations mean the two bulbs are not interchangeable between front and rear positions.
Both the 1157 and 1156 are ANSI-standardized bulb types recognized in the United States and Canada, indicating conformance to a defined set of electrical and physical tolerances.