GMC R2500 Dome Light Bulb Size

The GMC R2500 dome light requires a 211-2 bulb size for proper installation within the interior overhead lighting fixture. Data for the specified bulb covers the 1987 to 1989 range.

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
1987-1989	211-2

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, SV8.5 base. 12V, 12W.	211-2

Other Locations

Additional Notes

The 211-2 is the sole dome light bulb type listed for the GMC R2500 across the 1987-1989 model years.
The 211-2 follows the ANSI standard, meaning it conforms to the electrical and physical specifications established by the American National Standards Institute, with recognized equivalency in Canada.
The 211-2 is a festoon-style bulb, a form factor characterized by a cylindrical body with metal caps at each end that make contact with spring-loaded holders inside the fixture.
The bulb body is 41mm in length, which is the measurement used to match festoon bulbs to their corresponding dome light housings.
The 211-2 uses an SV8.5 base, a designation that refers to the 8.5mm width of the end caps on a festoon bulb.
The 211-2 operates at 12 volts and consumes 12 watts, values consistent with standard 12-volt automotive electrical systems.
Because festoon bulbs are sized by both length and base width, substituting a festoon bulb of a different length or base size would result in an improper fit within the GMC R2500 dome light housing.