The Isuzu Rodeo turn signal uses 1156NA, P21W, and 1156 bulb sizes for the specific lighting components. Data for the lighting specifications covers the range from 1995 through 2004.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu Rodeo uses the 1157NA for the front turn signal and the 1156NA for the rear turn signal across the full 1991-2004 model range.
The 1157NA is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, which allows it to serve both signaling and parking light functions from a single housing.
The 1156NA is a single-filament bulb rated at 12V and 21W, dedicated solely to the turn signal function at the rear.
Both the 1157NA and 1156NA use bayonet-style bases, though they are not interchangeable. The 1157NA uses a BAY15d base with two offset pins to accommodate its dual-filament design, while the 1156NA uses a BA15s base with a single contact pin.
The physical difference in pin configuration between the BAY15d and BA15s bases prevents accidental cross-installation between the front and rear bulbs.
Both bulbs feature natural amber glass, meaning the amber color is produced by the glass envelope itself rather than by a coated or painted surface, which generally results in more consistent color output over the bulb's service life.
Both the 1157NA and 1156NA conform to ANSI standards applicable in the United States and Canada, indicating standardized electrical and photometric performance requirements.