Mitsubishi Montero Back Up Light Bulb Size

The Mitsubishi Montero back up light utilizes 7440, P21W, and 1156 bulb sizes depending on the specific version of the vehicle. Available data for the lighting components covers the range from 1983 to 2006.

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
2001-2006	7440
1983-2000	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Mitsubishi Montero back up light specifications cover model years 1983 through 2006, with two distinct bulb types used across that span.
The 1156 bulb is specified for the Mitsubishi Montero from 1983 through 2000, making it the bulb type associated with the greater portion of the model's production history in these specifications.
The 7440 bulb is specified for model years 2001-2006, reflecting a change in socket type that occurred at that point in the Montero's production.
Both the 7440 and 1156 are ANSI-standard bulbs rated at 12 volts and 21 watts, meaning they share identical electrical output despite their physical differences.
The 7440 is a T20 wedge-base bulb, meaning it is held in its socket by the wedge shape of its base rather than by a locking mechanism.
The 1156 uses a BA15s bayonet base, a single-contact bayonet fitting that locks into its socket with a twist.
Because the 7440 and 1156 use fundamentally different base types, one is not a direct physical substitute for the other, even though their wattage and voltage ratings are identical.
Both bulbs are single-filament designs, which is consistent with their application as back up lights, a function that requires only an on or off state.
The ANSI designations for both bulbs apply to the US and Canadian markets, indicating these specifications are relevant to North American-market Montero vehicles.