The Isuzu Trooper side marker requires a 194 bulb size for proper illumination and function. Data for the specific component covers the period from 1995 through 2002.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu Trooper uses two distinct bulb types across its front and rear side marker positions: the 194 and the 1157, both of which conform to ANSI standards recognized in the United States and Canada.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W. Its wedge base design means it is held in place by the socket itself rather than by a separate locking mechanism.
The 1157 is a dual-filament bulb fitted with a BAY15d bayonet base, rated at 12V with a 21W high filament and a 5W low filament. The dual-filament construction allows a single bulb to serve two brightness levels within one housing.
The front side marker position on the Isuzu Trooper calls for the 194 bulb across all listed model years, spanning 1984-2002.
The rear side marker position on the Isuzu Trooper calls for the 1157 bulb across the listed model years 1994-2002.
The 194 and 1157 are not interchangeable. They differ in base type, wattage, filament count, and physical form, making cross-substitution between the front and rear marker positions incompatible.
The BAY15d bayonet base of the 1157 features two offset pins, a detail that prevents incorrect insertion of physically similar but electrically different single-filament bayonet bulbs into the same socket.
At 3.78W, the 194 draws considerably less power than the 1157, which reflects its role as a low-intensity marker lamp rather than a combined stop and tail light function.