Isuzu Pickup front and rear turn signal bulbs utilize 1034, 1157, 2057, 1156, and 1073 sizes depending on location and model variation. The replacement chart covers 1981 through 1995 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The front turn signal on the Isuzu Pickup used three distinct bulb types across the 1981-1995 model years: the 2057 for 1981-1983, the 1157 for 1984-1993, and the 1034 for 1994-1995.
The 1157 and 1034 are both dual-filament bulbs sharing the BAY15d bayonet base and a 12V rating, with the key difference being wattage. The 1157 draws 21W on its high filament and 5W on its low filament, while the 1034 draws 21W and 5W respectively, making the 1034 a direct variant of the 1157.
The 2057, used in the front turn signal position for 1981-1983, is also a dual-filament BAY15d bulb but draws notably more power at 26.9W and 8W, making it the brightest of the three front turn signal bulbs specified.
Although the 1157 and 2057 share the same BAY15d base and are physically interchangeable in terms of fitment, their differing wattage outputs mean substituting one for the other may produce different light intensity than the original specification.
The rear turn signal on the Isuzu Pickup used the 1156 for nearly all model years covered, with the sole exception being 1985, which specified the 1073.
The 1156 and 1073 are both single-filament bulbs with the BA15s bayonet base, operating at 12V. The 1156 draws 21W, while the 1073 draws 13W, making the 1073 a lower-wattage variant of the 1156.
Because the front turn signal bulbs (1034, 1157, 2057) use the BAY15d dual-contact base and the rear turn signal bulbs (1156, 1073) use the BA15s single-contact base, the front and rear bulbs are not interchangeable with each other.
The shift from the 2057 to the 1157 in the front turn signal position beginning with the 1984 model year represents a reduction in high-filament wattage from 26.9W to 21W.
The 1985 rear turn signal specification of the 1073 at 13W stands apart from every other model year in the rear position, all of which specified the higher-wattage 1156 at 21W.
All bulb types listed across both front and rear turn signal positions conform to ANSI standards applicable in the United States and Canada.