Chevrolet Biscayne Turn Signal Indicator Bulb Size

The Chevrolet Biscayne turn signal indicator utilizes bulb sizes 194, 1895, 1445, 257, and 57 depending on the specific version of the vehicle. Data for the bulb sizes covers the range from 1958 through 1972.

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
1968-1972	194
1966-1967	1895
1964-1965	1445
1963	257
1962	57
1959-1961	257
1958	57

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 0.9W.	1895
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 2W.	1445
ANSI standard (US & Canada). Festoon or BA9s base instrument bulb. 12V, 2W.	257
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 1W.	57

Other Locations

Additional Notes

The Chevrolet Biscayne turn signal indicator used five distinct bulb types across its production run from 1958 to 1972, each carrying an ANSI standard rating for the US and Canadian markets.
The 194 bulb, a T10 miniature wedge type rated at 12V and 3.78W, was the specified fitment for the Biscayne from 1968 to 1972. The wedge base design requires no separate socket retainer, as the bulb body itself locks into the housing.
The 1895 bulb is a T5 miniature wedge type rated at 12V and 0.9W, making it the lowest-wattage bulb in these specifications. It was fitted to the 1966 and 1967 model years.
Although both the 194 and 1895 bulbs share a wedge base construction, their T10 and T5 tube sizes are not interchangeable. Substituting one for the other would result in an incorrect physical fit within the housing.
The 1445 bulb uses a BA9s bayonet base and is rated at 12V and 2W. It was the specified fitment for the 1964 and 1965 model years.
The 257 bulb, also rated at 12V and 2W, is listed as accepting either a festoon or BA9s base configuration. It was specified for the 1959-1960 and 1961 model years, as well as 1963.
The 57 bulb is a single-filament BA9s type rated at 12V and 1W. It was specified for 1958 and 1962. Despite sharing the BA9s base with the 1445 bulb, the two differ in wattage and are not rated as direct substitutes.
The BA9s base type recurs across three separate bulb numbers in these specifications, specifically the 1445, 257, and 57. Physical base compatibility alone does not confirm electrical or optical interchangeability between these types.