GMC K3500 License Plate Bulb Size

The GMC K3500 license plate light uses 194 and 67 bulb sizes for the exterior illumination of the rear vehicle identification tag. Provided information covers the span from 1979 to 2000 for the specified truck components.

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 K3500 uses two distinct bulb types for the license plate position across its model years: the 194 and the 67.
The 194 bulb is specified for the GMC K3500 across the 1988-2000 model years.
The 194 is a T10 miniature wedge bulb rated at 12 volts and 3.78 watts, conforming to ANSI standards for the US and Canadian markets.
The wedge base of the 194 bulb is held in place by tension from the socket itself, with no separate locking mechanism or base pin required.
The 67 bulb is specified for the 1979-1986 model years of the K3500.
The 67 uses a BA15s single-contact bayonet base, which is a twist-lock fitting mechanically incompatible with the wedge socket used by the 194.
The 67 is rated at 12 volts and 8 watts, making it more than twice the wattage of the 194, and it is described as a lower-wattage variant of the 1156 bulb family.
Because the 194 and the 67 use physically different base types, a wedge-socket housing and a bayonet-socket housing are not interchangeable, and the bulb type must correspond to the socket present in the vehicle.