GMC C3500 Map Light Bulb Size

The GMC C3500 map light utilizes bulb sizes 168, 561, and 211-2 depending on the specific version of the lighting component. Data for the lighting specifications covers the range from 1993 to 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
1999-2000	168
1998	561
1996-1997	168
1995	211-2
1994	168
1993	211-2

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561
ANSI standard (US & Canada). Festoon bulb, 41mm length, SV8.5 base. 12V, 12W.	211-2

Other Locations

Additional Notes

The GMC C3500 map light draws from three distinct bulb types across its 1993-2000 model years: the 168, 561, and 211-2.
The 168 is the most frequently specified bulb across this range, covering the 1994, 1996-1997, 1999-2000 model years.
The 168 is a T10 miniature wedge bulb rated at 12V and 4.9W, conforming to ANSI standards for the US and Canadian markets.
The wedge base of the 168 relies on the bulb's glass envelope and wire leads to make contact with the socket, requiring no separate metal base.
The 211-2 is a festoon-type bulb with an SV8.5 base, rated at 12V and 12W, and is specified for the 1993 and 1995 GMC C3500 map light.
The 561 is also a festoon-type bulb rated at 12V and 12W, but it uses end-cap contacts and a 44mm length, and is specified exclusively for the 1998 model year.
Festoon bulbs make contact at both ends of the tube, which distinguishes their socket design from the wedge-type socket used by the 168.
Although the 211-2 and 561 share the same voltage and wattage ratings, their physical lengths differ: the 211-2 is 41mm while the 561 is 44mm, making them non-interchangeable despite the electrical similarity.
The 168 operates at 4.9W, considerably lower than the 12W output of both festoon types, reflecting a fundamental difference in the light output and thermal characteristics between the wedge and festoon formats used across these model years.
All three bulb types conform to ANSI standards applicable in both the US and Canada.