Mitsubishi Eclipse Map Light Bulb Size

Additional Notes

• The Mitsubishi Eclipse map light uses two distinct bulb types across its model years: the DE3175 and the 12961.
• The DE3175 is an ANSI-standardized festoon bulb rated at 12 volts, measuring 31mm in length with end-cap contacts. Its festoon design means it seats by pressing lengthwise between two spring-loaded contact points rather than inserting into a socket.
• The 12961 is a Philips part number designating a miniature wedge-style T10 bulb with a W2.1x9.5d base, rated at 12 volts and 5 watts. Its wedge base is inserted directly into a friction-fit socket without a separate locking mechanism.
• Because the DE3175 uses end-cap contacts and the 12961 uses a wedge base, the two bulb types are not interchangeable. The socket type in the vehicle determines which bulb is compatible.
• The DE3175 is the more prevalent fitment for the Mitsubishi Eclipse map light, covering model years 1990-2002, 2004, and 2006-2011, with the exception of 1993, 2001, 2003, 2005, and 2008.
• The 12961 wedge bulb applies to the 2001, 2003, 2005, and 2008 Eclipse model years, as well as 1993.
• The DE3175 designation follows ANSI standards recognized in both the United States and Canada, which means equivalent bulbs from different manufacturers sharing that designation are generally produced to the same physical and electrical specifications.
• The 12961 carries a manufacturer-specific Philips part number rather than a universal ANSI code, though its T10 form factor and W2.1x9.5d base are widely recognized industry classifications.