GMC C1500 Suburban Map Light Bulb Size

Additional Notes

• The GMC C1500 Suburban map light uses two distinct bulb types across its model years: the 168 and the 211-2, both of which are ANSI-standardized components rated for use in the US and Canada.
• The 168 bulb is a T10 miniature wedge type operating at 12 volts and 4.9 watts, while the 211-2 is a festoon bulb with an SV8.5 base, a 41mm length, and a significantly higher draw of 12 watts at 12 volts.
• Because the 168 and 211-2 differ in both physical form and wattage, the two bulb types are not interchangeable with one another.
• The wedge-style base of the 168 bulb seats by friction fit into a tapered socket, whereas the 211-2 uses an SV8.5 festoon base that seats by spring tension between two end contacts.
• The GMC C1500 Suburban (1996-1998) uses the 211-2 festoon bulb for the map light across three consecutive model years.
• The 1999 model year uses the 168 wedge bulb, while the immediately preceding 1996-1998 model years use the 211-2, indicating a socket change occurred between the 1998 and 1999 production runs.
• The 1993 model year also specifies the 211-2, making it the only early-production year in these specifications to use the festoon type, as the surrounding years specify the 168 wedge bulb.
• The higher wattage of the 211-2 at 12 watts, compared to 4.9 watts for the 168, reflects the larger physical size and greater light output typical of festoon bulbs used in interior reading and map light applications.