Ford F-150 Automatic Transmission Indicator Bulb Size

The Ford F-150 automatic transmission indicator uses bulb sizes 194, 37, and 1445 depending on the specific version of the component. Data for the light sources covers the range from 1975 to 1996.

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
1992-1996	194
1989-1991	37
1975-1979	1445

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, 1W.	37
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 2W.	1445

Other Locations

Additional Notes

The Ford F-150 automatic transmission indicator uses three distinct bulb types across the 1975-1996 model years: the 194, the 37, and the 1445.
All three bulb types conform to ANSI standards recognized in both the United States and Canada.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, and it fits the Ford F-150 automatic transmission indicator for the 1992-1996 model years.
The T10 wedge form factor uses a tapering plastic base that is pressed directly into a socket, requiring no separate bulb holder or locking mechanism.
The 37 is a T5 miniature wedge bulb rated at 12V and 1W, and it applies to the 1989-1991 model years.
The T5 designation indicates a smaller wedge base than the T10, meaning the 37 and the 194 are not physically interchangeable despite both being wedge-type bulbs.
The 1445 is a single-filament bulb with a BA9s bayonet base rated at 12V and 2W, and it fits the 1975-1979 model years.
The BA9s base is a miniature bayonet cap with a 9mm collar, a fundamentally different mounting type from the wedge base used by the 194 and 37, making cross-substitution between these generations incompatible.
At 1W, the 37 bulb draws the least power of the three types listed, while the 194 at 3.78W draws the most.
All three bulb types operate on a 12V circuit, consistent with standard automotive electrical systems.