Mercury Colony Park Back Up Light Bulb Size

The Mercury Colony Park back up light utilizes 1076, 1141, 1156, and P21W bulb sizes for the illumination system. Available data for the specified vehicle covers the range from 1957 through 1991.

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
1987-1991	1156
1974	1156
1973	1076
1966-1972	1156
1963-1965	1141
1958-1962	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. Variant of 1156. 12V, 8W.	1076
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1141

Other Locations

Additional Notes

The Mercury Colony Park back up light specifications span model years 1957 through 1991, with the 1156 bulb appearing across the majority of those years, making it the most frequently specified bulb type for this application.
The 1156 is an ANSI-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, which is a single-contact base with a 15mm collar.
The 1141 is also an ANSI-standard single-filament bulb rated at 12V and 21W with a BA15s bayonet base, sharing identical voltage and wattage ratings with the 1156.
Although the 1156 and 1141 share the same BA15s base type and electrical ratings, they carry distinct ANSI designations, and the specifications treat them as separate fitments across different model years.
The Mercury Colony Park (1987-1991) uses the 1156 bulb for the back up light across all five of those model years.
The 1141 bulb is specified for the 1957 and 1963-1965 model years, while the 1156 is specified for 1958-1962 and 1966 onward, indicating that the two bulbs were not interchangeable within the factory fitment record despite their matching electrical ratings.
The 1076 is an ANSI-standard single-filament bulb with a BA15s bayonet base rated at 12V and 8W, and it is specified exclusively for the 1973 model year, setting it apart from all other years in the record by its significantly lower wattage output.
All three bulb types in these specifications share the BA15s bayonet base format, meaning the physical mounting interface is consistent across the entire model range, even where the bulbs themselves differ in wattage or designation.
The 1076 is described as a variant of the 1156, yet its 8W rating is substantially lower than the 1156's 21W rating, a difference that affects light output and makes the two bulbs functionally distinct despite their shared base type.