Dodge Diplomat Dome Light Bulb Size

Additional Notes

• The dome light bulb specifications for the Dodge Diplomat span the 1977-1989 model years, covering thirteen model years in total.
• Two bulb types appear across these specifications: the 211-2 festoon bulb and the 912 wedge bulb, both rated at 12V and 12W.
• The 211-2 is a festoon-style bulb with a 41mm length and an SV8.5 base, meaning it seats by pressing lengthwise between two spring clips rather than inserting into a socket.
• The 912 is a T15 wedge bulb, a form factor that inserts directly into a wedge-style socket without a separate base or pins.
• Both bulb types conform to ANSI standards recognized in the United States and Canada.
• The 912 is a variant of the 921 bulb, which shares the same T15 wedge form factor but differs in wattage; the 912 is rated at 12W while the 921 is typically rated at 18W, making them physically similar but not electrically identical.
• The 211-2 festoon type is specified for the Dodge Diplomat across the majority of model years, including 1977-1982, 1984-1986, and 1987-1989.
• The 912 wedge type is specified for the 1981 and 1983 model years, representing exceptions within an otherwise festoon-dominant fitment history.
• Because the 211-2 and 912 use fundamentally different mounting systems, one type is not a drop-in substitute for the other regardless of their matching voltage and wattage ratings.
• The alternating bulb types across certain model years indicate that the dome light housing design changed at least twice during the Diplomat's production run.