Chevrolet Chevelle Automatic Transmission Indicator Bulb Size

Additional Notes

• The automatic transmission indicator positions on the Chevrolet Chevelle are served by three distinct bulb types across the listed model years: the 168, the 1895, and the 1445, all conforming to ANSI standards applicable in the United States and Canada.
• The 1895 is the most frequently specified bulb across these years, appearing in the 1966-1968 and 1970-1971 model years. It is a T5 miniature wedge bulb rated at 12V and 0.9W, making it the lowest-wattage type among the three specified.
• The 1445 bulb is specified for the Chevrolet Chevelle in 1964, 1965, and 1969. Unlike the wedge-type bulbs in this application, the 1445 uses a BA9s bayonet-style base and carries a 12V, 2W rating with a single filament.
• The 168 bulb is specified exclusively for the 1973 model year. It is a T10 miniature wedge type rated at 12V and 4.9W, which is notably higher in wattage than both the 1895 and the 1445 used in earlier years.
• The T5 envelope of the 1895 is physically smaller than the T10 envelope of the 168. A T10 bulb body is approximately twice the width of a T5, which affects socket fitment and makes these two wedge types non-interchangeable despite sharing the same base style.
• The 1445 and the 1895 are both rated at 12V but differ in base type entirely. The 1445 uses a BA9s pin base while the 1895 uses a wedge base, so these two bulbs are not interchangeable regardless of their shared voltage rating.
• The wattage difference between the 1895 at 0.9W and the 168 at 4.9W is significant for indicator circuit applications, as substituting a higher-wattage bulb into a socket designed for a lower-wattage type can exceed the thermal and electrical tolerances of the surrounding components.
• All three bulb types in these specifications operate on a 12V system, consistent with the standard automotive electrical architecture of the era covered by these model years.