GMC Sierra Turn Signal Indicator Bulb Size

GMC Sierra turn signal indicator bulb uses a 74 size bulb for this component. The replacement chart covers 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
1999-2002	74

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

The GMC Sierra uses the ANSI-standard 74 bulb for its turn signal indicator across the 1999-2002 model years.
The 74 bulb follows a T5 miniature wedge form factor, which means it uses a wedge-shaped base rather than a bayonet or screw-type fitting.
Operating at 12 volts and 1.4 watts, the 74 bulb is a low-power unit suited for instrument panel and indicator applications rather than exterior lighting.
The T5 designation refers to the bulb's tubular envelope width, expressed in eighths of an inch, placing it among the smallest bulb sizes used in automotive applications.
The wedge base design of the 74 bulb means the filament leads extend directly through the glass base, eliminating the need for a separate metal cap or socket pins.
Because the 74 is an ANSI-standardized bulb, it is recognized under the same specification in both the United States and Canada, reflecting a shared North American automotive lighting standard.