Mercury Commuter Back Up Light Bulb Size

The Mercury Commuter back up light utilizes 1156, 1141, 1073, and P21W bulb sizes depending on the specific production period for the vehicle. Available data for the bulb sizes covers the range from 1957 to 1968.

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
1968	1156
1967	1141
1966	1156
1965	1141
1961-1964	1156
1959-1960	1073
1958	1156
1957	1141

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. 12V, 21W.	1141
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	1073

Other Locations

Additional Notes

The Mercury Commuter back up light specifications span model years 1957 through 1968, covering three distinct bulb types across that range: the 1156, the 1141, and the 1073.
The 1156 bulb is the most frequently specified type for the Mercury Commuter, appearing in the 1958, 1961-1964, 1966, and 1968 model years.
All three bulb types in these specifications share the BA15s bayonet base, a single-contact base design that uses a 15mm barrel with a single locating pin on the side.
The 1156 and 1141 are both rated at 12V and 21W, making them electrically equivalent despite carrying different ANSI designations.
Because the 1156 and 1141 share the same BA15s base, voltage, and wattage, physical fitment between the two is possible, though they remain distinct part numbers under ANSI standards.
The 1073 bulb, specified for the Mercury Commuter in 1959 and 1960, operates at 12V but draws only 13W, making it a lower-output bulb compared to the 1156 and 1141.
Although the 1073 shares the BA15s bayonet base with the 1156 and 1141, its reduced wattage means it is not a direct electrical equivalent, and substitution between these types would result in a difference in light output.
All three bulb types conform to ANSI standards applicable in both the United States and Canada.
The 1141 is specified for the 1957, 1965, and 1967 model years of the Mercury Commuter, making it the least frequently appearing of the three bulb types in this application.