Mitsubishi Galant Map Light Bulb Size

Additional Notes

• The Mitsubishi Galant map light uses two distinct festoon bulb sizes across its model years: the DE3423 for 2004-2012 and the DE3175 for 1999-2003, with both conforming to ANSI standards applicable in the US and Canada.
• The DE3423 is a 41mm festoon bulb operating at 12V with end-cap contacts, making it physically longer than the DE3175, which shares the same contact style and voltage rating but measures 31mm in length.
• Because the DE3423 and DE3175 differ in length, they are not interchangeable despite sharing the same festoon form factor and end-cap contact design.
• For the 1995-1998 model years, the Mitsubishi Galant map light fitment splits based on whether the vehicle is equipped with a sunroof, requiring the DE3175 festoon bulb in sunroof-equipped trims and the 12961 in non-sunroof trims.
• The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W, which is a fundamentally different bulb type from the festoon-style DE3175 used in the sunroof variant of the same model years.
• The wedge base of the 12961 and the end-cap contacts of the DE3175 represent incompatible mounting systems, meaning the two bulbs specified for 1995-1998 cannot substitute for one another regardless of voltage compatibility.
• The DE3423 festoon bulb is the most widely specified map light bulb across the Galant's listed model range, covering nine consecutive model years from 2004 through 2012.
• Festoon bulbs, such as the DE3423 and DE3175, seat by spring tension between two end caps within a cylindrical housing, a mounting method distinct from the wedge-style socket used by the 12961.