Buick Roadmaster front and rear turn signal bulbs utilize sizes 2057NA, 1034, 1154, 2057, and 1073 across various production configurations. The replacement chart covers 1950 through 1991 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BAY15d bayonet base is a dual-contact base with offset pins, designed to prevent incorrect bulb orientation during installation. It appears across the majority of bulbs specified for the Buick Roadmaster, including the 2057NA, 2057, 1034, 1154, and 1129 types.
The 1073 bulb, specified for the rear turn signal on the Roadmaster from 1954-1957, uses a BA15s bayonet base rather than BAY15d. The BA15s is a single-contact base, which reflects the 1073 being a single-filament bulb. This base type is physically incompatible with BAY15d sockets.
The 2057NA and 2057 are both rated at 12V with a 26.9W/8W dual-filament output. The 2057NA differs from the 2057 solely in its natural amber glass, which produces the amber color required for turn signals without relying on a colored lens.
The 2057NA is specified for the 1991 Roadmaster front turn signal, while the 2057 is specified for the rear. Because the 2057NA and 2057 share identical voltage and wattage ratings, the only functional distinction between the two positions is the amber glass of the front bulb.
The 1154 bulb, specified for the front turn signal on the Roadmaster from 1950-1953, is rated for both 6V and 12V operation. This dual-voltage compatibility reflects the transitional period in automotive electrical systems during the early 1950s, when the industry was shifting from 6-volt to 12-volt standards.
The 1034 and 1129 bulbs share the same wattage rating of 21/5W and both use the BAY15d base, making them dimensionally and electrically similar. However, they are distinct ANSI part numbers and are not listed as interchangeable within these specifications.
The front turn signal on the Roadmaster used the 1034 bulb from 1954-1958, while the rear turn signal used the 1073 for 1954-1957 and then switched to the 1034 in 1958. The 1958 model year is the only one in that era where the front and rear turn signals share the same bulb type.
All bulbs listed in these specifications conform to ANSI standards applicable to the United States and Canada, indicating standardized physical and electrical tolerances across all specified part numbers.