Chevrolet Cavalier Automatic Transmission Indicator Bulb Size

Additional Notes

• The Chevrolet Cavalier automatic transmission indicator uses three distinct bulb sizes across its model years: the 73, 74, and 168, all of which conform to ANSI standards recognized in both the United States and Canada.
• The 168 bulb is the most frequently specified type across the listed model years, covering the 1983-1989 range of the Cavalier's automatic transmission indicator position.
• The 168 is a T10 miniature wedge bulb rated at 12V and 4.9W, making it the highest-wattage bulb among the three types specified for this application.
• The 73 and 74 bulbs are both T5 miniature wedge types sharing identical electrical ratings of 12V and 1.4W, meaning they differ in designation but not in voltage or wattage output.
• Despite their shared electrical characteristics, the 73 and 74 are separate ANSI designations, and interchangeability between them is not confirmed by the specifications provided.
• The 1991 Chevrolet Cavalier is the only model year in the listed range to use the 74 bulb, while the 1992-1994 years use the 73, representing a shift between two physically similar but distinctly numbered T5 wedge types.
• The T5 and T10 designations refer to the bulb's tubular envelope size, with T5 being narrower than T10. These two form factors are not interchangeable, as the socket housings are sized to match each specific type.
• The transition from the 168 (T10) to the 73 or 74 (T5) between the 1989 and 1991 model years reflects a significant change in both bulb size and wattage for the transmission indicator circuit.