GMC C2500 Dome Light Bulb Size

The GMC C2500 dome light requires a 211-2 bulb size for the interior overhead lighting component. Available data covers the span from 1979 through 2000 for the specified vehicle and lighting application.

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
2000	211-2
1999	211-2 (For Vehicle With Standard Cab & Chassis, Extended Cab & Chassis)
1988-1998	211-2
1979-1986	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 GMC C2500 dome light uses the 211-2 bulb across all listed model years from 1979 to 2000, with the sole exception of a fitment note specific to the 1999 model year.
The 211-2 is a festoon-type bulb, meaning it is cylindrical in shape and held in place by spring-loaded end caps rather than a socket with a plug-in base.
It carries an SV8.5 base designation, which refers to the 8.5mm end cap width standard used to classify festoon bulbs of this type.
The bulb operates at 12 volts and 12 watts, which is consistent with standard automotive interior lighting power levels.
The 211-2 conforms to ANSI standards recognized in both the United States and Canada, placing it within a regulated specification for electrical and physical performance.
Its physical length is 41mm, a measurement that determines socket compatibility and must match the housing span of the dome light fixture.
For the 1999 GMC C2500, the 211-2 fitment is specified for vehicles with a Standard Cab and Chassis or an Extended Cab and Chassis configuration.
Because festoon bulbs rely on physical length for retention, substituting a bulb of a different length risks poor contact or failure to seat properly, even if the wattage and voltage ratings are otherwise equivalent.