Isuzu Pickup Back Up Light Bulb Size

The Isuzu Pickup back up light uses bulb sizes 1073, 1156, and P21W depending on the specific version of the vehicle. Available data covers the range from 1981 to 1995.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1984-1995	1156
1982-1983	1073
1981	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	1073

Other Locations

Additional Notes

The Isuzu Pickup uses the 1156 bulb for the back up light across the majority of its model years, specifically 1981 and 1984-1995.
The 1156 is an ANSI-standardized single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base.
The BA15s bayonet base designation indicates a single-contact base with a 15mm collar, a common format in automotive lighting applications.
The 1982-1983 Isuzu Pickup back up light takes the 1073 bulb instead of the 1156.
The 1073 shares the same BA15s bayonet base and 12V operating voltage as the 1156 but draws only 13W, making it a lower-wattage variant.
Despite their physical compatibility due to the shared BA15s base, the 1073 and 1156 are not interchangeable without a difference in light output, as the wattage gap between the two is 8W.
Both the 1156 and 1073 carry ANSI standardization applicable to the US and Canadian markets.
The single-filament construction of both bulb types means each serves only one lighting function, which is consistent with the dedicated role of a back up light.