Ford F-250 Check Engine Bulb Size

The Ford F-250 check engine light requires bulb size 194 or PC74 depending on the specific instrument cluster configuration. Data for 194 and PC74 bulbs covers the range from 1994 to 1999.

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
1999	PC74
1994-1996	194

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T5) with printed circuit board twist-lock socket, for instrument clusters. 12V, 1.4W.	PC74
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194

Other Locations

Additional Notes

The Ford F-250 check engine light uses two distinct bulb types across its model years: the PC74 for the 1999 model year and the 194 for the 1994-1996 model years.
Both the PC74 and 194 are ANSI-standardized miniature wedge bulbs rated for 12V systems, though they differ in wattage and socket type.
The 194 is a T10 miniature wedge bulb operating at 3.78W, a common size used across many automotive instrument panel applications.
The PC74 is a T5 miniature wedge bulb rated at 1.4W, notably lower in wattage than the 194, reflecting its smaller physical profile.
The PC74 uses a printed circuit board twist-lock socket, which is a specialized mounting interface designed specifically for instrument cluster printed circuit boards.
The twist-lock socket of the PC74 makes it physically incompatible with the standard wedge socket used by the 194, meaning the two bulb types are not interchangeable despite both being miniature wedge designs.
The T5 and T10 designations refer to the tubular bulb body width in eighths of an inch, placing the PC74 at a narrower profile than the 194.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating consistent electrical and dimensional specifications within those markets.