GMC C2500 License Plate Bulb Size

The GMC C2500 license plate component requires bulb sizes 194 and 67 for proper illumination across various vehicle generations. Provided technical data covers the production span from 1979 through 2000.

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
1988-2000	194
1979-1986	67

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 8W.	67

Other Locations

Additional Notes

The GMC C2500 uses two distinct bulb types for the license plate position across its model years: the 194 and the 67.
The 194 bulb is the license plate bulb for the GMC C2500 covering model years 1988-2000.
The 67 bulb applies to model years 1979-1986.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, conforming to ANSI standards for the US and Canada.
The wedge base of the 194 bulb means it is held in place by tension from the socket itself, with no separate locking mechanism or bayonet pins.
The 67 bulb uses a BA15s single-contact bayonet base and is rated at 12V and 8W, also conforming to ANSI standards for the US and Canada.
The BA15s bayonet base of the 67 bulb is a single-filament design, distinguishing it from dual-filament bayonet bulbs that share a physically similar base but serve different functions.
The 67 bulb is described as a lower wattage variant of the 1156, meaning the two share a base type but are not interchangeable due to the wattage difference.
The 194 and 67 bulbs use incompatible base types, a wedge and a bayonet respectively, so they are not interchangeable between the two model year groups.
At 8W, the 67 draws more than twice the wattage of the 194 at 3.78W, reflecting a difference in socket and circuit design between the earlier and later C2500 generations.