Ford Pinto License Plate Bulb Size

The Ford Pinto license plate light requires 168, 89, 631, or 97 bulb sizes depending on the specific version. Data for the lighting components covers the 1971 to 1980 range.

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
1977-1980	168
1974	89
1973	631
1971-1972	97

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	89
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W.	631
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97

Other Locations

Additional Notes

The Ford Pinto license plate bulb specifications span the 1971-1980 model years, with four distinct bulb types used across that period: the 168, 89, 631, and 97.
The 168 bulb is the most frequently specified type, covering the Ford Pinto from 1977-1980. It is a T10 miniature wedge bulb rated at 12V and 4.9W, conforming to ANSI standards for the US and Canada.
The T10 wedge base of the 168 bulb uses a wedge-style pin-free connection, where the glass envelope itself acts as the retention mechanism within the socket.
The 89, 631, and 97 bulbs all share the BA15s bayonet base and are each described as variants of the 1156. Despite this shared base type, their wattage ratings differ, which affects their interchangeability.
The 631 bulb, specified for the 1973 Ford Pinto, is rated at 21W, making it the highest-wattage bulb in these specifications. The 89 and 97 bulbs are both rated at 13W, though they remain distinct part numbers.
Because the BA15s bayonet base is physically identical across the 89, 631, and 97 bulbs, a socket fit does not confirm electrical compatibility. The wattage difference between the 631 (21W) and the 89 or 97 (13W) means substitution between these types is not supported by the specifications.
The 168 wedge-base bulb and the BA15s bayonet-base bulbs (89, 631, 97) use fundamentally different socket types and are not interchangeable with one another regardless of voltage rating.
All four bulb types are rated at 12V, consistent with standard automotive electrical systems.