Chevrolet Equinox Map Light Bulb Size

Additional Notes

• The Chevrolet Equinox map light uses two distinct bulb sizes across its model years, with the 906 fitted to the 2005-2009 model years and the 12961 fitted to the 2010-2018 model years.
• Both the 12961 and the 906 belong to the T10 miniature wedge bulb family and share the same physical wedge base form factor, meaning they occupy the same general bulb category.
• Despite sharing the T10 form factor, the two bulbs are not electrically identical. The 906 operates at 8W while the 12961 operates at 5W, a difference that affects heat output and current draw.
• The 12961 is a Philips part number designation rather than an ANSI industry-standard code, which means sourcing equivalent replacements requires cross-referencing to the underlying T10 W2.1x9.5d specification.
• The W2.1x9.5d base designation on the 12961 describes a specific wedge base width of 2.1mm and a pin spacing of 9.5mm, which defines its physical fitment into the socket.
• The 906 carries an ANSI standard designation recognized across the United States and Canada, making it broadly available through multiple manufacturers under the same numeric code.
• Both bulbs operate on a 12V electrical system, consistent with standard automotive low-voltage circuits.
• The wattage difference between the two bulbs means the 906 draws more power from the vehicle's electrical system than the 12961, which is relevant when considering socket and wiring tolerances rated for the original specification.