Mercury Commuter Map Light Bulb Size

Additional Notes

• The Mercury Commuter map light specifications span model years 1962 through 1968, covering three distinct bulb types across that period.
• The 1895 bulb is the most frequently specified type in these records, appearing in the Mercury Commuter across the 1962-1965 model years.
• The 1895 is an ANSI-standard miniature wedge bulb rated at T5, operating at 12V with a draw of just 0.9W, making it among the lower-wattage units in these specifications.
• The 1816 bulb is specified for the 1966 and 1968 Mercury Commuter map light positions, with the 1967 model year using a different type entirely.
• The 1816 is also an ANSI-standard miniature wedge bulb, though it carries a T3.25 designation and draws 4W at 12V, placing it at a notably higher wattage than the 1895.
• Although both the 1816 and 1895 share a miniature wedge construction and 12V operating voltage, their wattage ratings and T-designations differ, and they are not interchangeable across the fitments listed here.
• The 1967 Mercury Commuter map light takes the 631 bulb, which is an ANSI-standard single-filament unit with a BA15s bayonet base, rated at 12V and 21W.
• The 631 is noted as a variant of the 1156 bulb family. Its BA15s bayonet base is physically distinct from the wedge base used by the 1816 and 1895, meaning cross-substitution between these types is not supported by the specifications.
• At 21W, the 631 draws substantially more power than either the 1816 or the 1895, reflecting a fundamentally different bulb category despite sharing the same 12V system voltage.
• All three bulb types listed carry ANSI standardization applicable to both the United States and Canada.