Chevrolet Blazer Check Engine Bulb Size

The Chevrolet Blazer check engine light utilizes PC74, 74, and 194 bulb sizes depending on the specific production period for the instrument cluster. Data for the light components covers the range from 1989 to 2003.

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
1995-2003	PC74
1993-1994	74
1989-1991	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 (T5). 12V, 1.4W.	74
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194

Other Locations

Additional Notes

The Chevrolet Blazer check engine light uses three distinct bulb types across its model years: the PC74, the 74, and the 194, all of which conform to ANSI standards applicable in the United States and Canada.
The PC74 is a T5 miniature wedge bulb rated at 12V and 1.4W. Its defining feature is a printed circuit board twist-lock socket, which is specifically designed for instrument cluster applications.
The 74 is also a T5 miniature wedge bulb rated at 12V and 1.4W, sharing the same voltage and wattage as the PC74 but lacking the twist-lock socket interface.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, making it a higher-wattage unit compared to the T5 types used in other model years of the same vehicle.
The Chevrolet Blazer (1995-2003) uses the PC74 for the check engine light, representing the longest continuous fitment period among the three bulb types listed.
The 1993-1994 model years use the standard 74 bulb. Although the 74 and PC74 share the same T5 form factor, voltage, and wattage, the socket type differs, and the two are not directly interchangeable.
The 1989-1991 model years use the 194 bulb. The T10 body of the 194 is physically larger than the T5 body of the 74 and PC74, making cross-substitution between these types incompatible.