GMC G3500 Dome Light Bulb Size

Additional Notes

• The GMC G3500 dome light uses the 211-2 bulb across all listed model years from 1979 to 1996.
• The 211-2 is a festoon-type bulb, meaning it is cylindrical in shape and mounts by pressing between two spring clips rather than inserting into a socket.
• The 211-2 bulb measures 41mm in length, which is the span between its two contact ends and determines whether it will seat correctly in the festoon holder.
• It uses an SV8.5 base designation, which refers to the 8.5mm width of the festoon cap contacts at each end of the bulb.
• The 211-2 operates at 12 volts and 12 watts, consistent with standard automotive electrical systems.
• The 211-2 is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared across manufacturers.
• Because the GMC G3500 dome light fitment is consistent across the entire 1979-1996 span, a single bulb specification applies to all listed model years without variation.
• Festoon bulbs such as the 211-2 are not interchangeable with wedge-base or bayonet-base bulbs, as those types require different socket configurations entirely.
• When replacing the 211-2, the 41mm length is a critical fitment factor, since festoon holders are sized to a specific span and an incorrect length will result in a poor or failed connection.