Buick Skylark Back Up Light Bulb Size

Additional Notes

• The Buick Skylark back up light specifications cover model years 1954 and 1961-1998, with the 1156 bulb appearing across the overwhelming majority of those years.
• The 1156 is an ANSI-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, and is recognized across both the US and Canadian markets.
• The BA15s bayonet base uses a single contact point at the base, which is a defining characteristic that distinguishes it from dual-contact bayonet variants and makes it non-interchangeable with those types.
• The Buick Skylark (1961-1998) uses the 1156 bulb for the back up light position across all listed model years in that span.
• The 1954 Skylark is specified with the 1073 bulb, which is also an ANSI-standard single-filament bulb sharing the same BA15s bayonet base as the 1156 but rated at a lower 13W output.
• Although the 1073 and 1156 share the same BA15s bayonet base, their wattage ratings differ at 13W and 21W respectively, and the two are not confirmed as interchangeable within these specifications.
• The single-filament construction of both the 1156 and 1073 means each bulb serves only one lighting function, as opposed to dual-filament bulbs that can serve two functions such as stop and tail simultaneously.
• The 12V operating voltage of both bulb types is consistent with standard automotive electrical systems used throughout the production years covered in these specifications.