GMC Sierra Instrument Panel Bulb Size

The GMC Sierra instrument panel requires 2 distinct bulb sizes, designated as 74 and 194, for proper illumination of dashboard components. A replacement chart documents the bulb specifications across vehicle production spanning 1999 to 2002.

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
2001-2002	74
2000	194
1999	74

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 1.4W.	74
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194

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Additional Notes

The GMC Sierra instrument panel uses two distinct bulb sizes across its model years: the 74 and the 194, both of which are ANSI-standardized miniature wedge bulbs for the US and Canadian markets.
The 74 bulb follows the T5 wedge form factor and operates at 12V with a rated wattage of 1.4W, placing it among the lower-wattage options used in instrument panel applications.
The 194 bulb follows the T10 wedge form factor and operates at 12V with a rated wattage of 3.78W, making it a notably higher-wattage draw compared to the 74 bulb despite both serving instrument panel functions.
The T5 and T10 designations refer to the outer envelope width of the bulb, expressed in units of one-eighth of an inch. The T10 is therefore physically larger than the T5, and the two are not interchangeable.
The GMC Sierra (2000) is specified with the 194 bulb, while the 1999, 2001, and 2002 model years are specified with the 74 bulb. The year 2000 therefore represents a fitment that differs from the surrounding model years.
Because the 74 and 194 bulbs differ in both physical size and wattage, substituting one for the other in a given model year would result in an incorrect fit for the instrument panel socket.