Ford F-100 License Plate Bulb Size

The Ford F-100 license plate light uses bulb sizes 97 and 194 depending on the specific version of the vehicle. Available information covers the time range from 1969 through 1983.

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
1981-1983	97
1975-1980	194
1969-1972	97

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194

Other Locations

Additional Notes

The Ford F-100 license plate position uses two distinct bulb types across its model years: the 97 and the 194, both of which are ANSI-standardized bulbs rated for use in the United States and Canada.
The 97 bulb is a single-filament type with a BA15s bayonet base, rated at 12 volts and 13 watts. It is a variant of the more widely known 1156 bulb, though the two are not identical and should not be treated as direct substitutes without verification.
The 194 bulb is a miniature wedge type in the T10 form factor, rated at 12 volts and 3.78 watts. Its wedge base design differs fundamentally from the bayonet base of the 97, making the two bulbs physically incompatible with each other's sockets.
The Ford F-100 (1969-1972) uses the 97 bulb for the license plate position.
Model years 1975-1980 use the 194 bulb, representing a shift from the bayonet-base 97 to the wedge-base T10 format.
The 97 bulb returns for the 1981-1983 model years, meaning the socket type reverts to a BA15s bayonet fitment after the preceding years used a wedge-base socket.
The wattage difference between the two bulbs is substantial. The 97 draws 13 watts while the 194 draws 3.78 watts, reflecting a significant difference in output and electrical load.
Because the 97 and 194 use incompatible base types, a bulb from one group cannot be physically installed in a socket designed for the other, regardless of voltage compatibility.