Chevrolet Caprice Dome Light Bulb Size

Additional Notes

• The Chevrolet Caprice dome light specifications reference four distinct bulb types across the full model range: the 12961, 561, 192, 1004, and 211-2, each with a different base type and wattage rating.
• The 211-2 is the most frequently specified bulb across the Caprice dome light data, appearing in model years 1966-1973 and again in 1976-1979. It is an ANSI-standard festoon bulb with an SV8.5 base, rated at 12V and 12W, and measures 41mm in length.
• The 561 festoon bulb is the second most common type in the specifications, used across multiple non-consecutive year groups. It shares the same 12V, 12W rating as the 211-2 but uses end-cap contacts and a 44mm length rather than the SV8.5 base, making the two bulbs non-interchangeable despite their identical voltage and wattage.
• The 12961 is a Philips-branded miniature wedge bulb of the T10 type with a W2.1x9.5d base, rated at 12V and 5W. It is specified for the Chevrolet Caprice (2011-2017), representing a notably lower wattage output compared to the festoon types used in earlier model years.
• The 1004 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with filaments at 21W and 5W. Its use in the dome light position for 1981-1982 is atypical, as dual-filament bulbs are more commonly associated with stop and tail light applications. The 1004 is noted as a variant of the 1157.
• The 192 is a T10 miniature wedge bulb rated at 12V and 3W, the lowest wattage of any bulb type in these specifications. It appears solely for the 1991 model year, positioned between years that specify the 561 festoon type, and the two are not interchangeable due to differing base types.
• The 561 and 211-2 festoon bulbs share the same voltage and wattage ratings but differ in physical length, at 44mm and 41mm respectively. Substituting one for the other risks a poor fit within the dome light housing, as festoon bulb holders are sized to the specific length of the intended bulb.
• The BAY15d bayonet base of the 1004 is physically incompatible with the festoon holders used by the 561 and 211-2, and equally incompatible with the wedge sockets used by the 12961 and 192, meaning no cross-substitution is possible between the 1004 and any other bulb type in these specifications.
• The T10 wedge base is shared by both the 12961 and the 192, as both are classified as T10 miniature wedge bulbs. However, their wattage ratings differ at 5W and 3W respectively, and the 12961 carries a specific Philips part designation rather than an ANSI standard number.
• The ANSI standard designations used for the 561, 192, 1004, and 211-2 indicate that these bulbs conform to standardized North American specifications covering base type, voltage, wattage, and physical form, whereas the 12961 is identified by a manufacturer part number under the Philips catalog system.