American Motors Javelin Dome Light Bulb Size

American Motors Javelin dome light bulb sizes include 561, 158, and 1004 specifications for interior illumination components. The replacement chart covers vehicle production spanning 1968 to 1974.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1972-1974	561
1971	158
1968-1970	1004

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3W.	158
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1004

Other Locations

Additional Notes

The American Motors Javelin dome light specifications span model years 1968-1974, covering three distinct bulb types across that period.
The 561 is the most frequently specified bulb in these records, appearing in the 1972-1974 Javelin dome light position. It is a festoon-style bulb measuring 44mm in length with end-cap contacts, rated at 12V and 12W under the ANSI standard.
Festoon bulbs like the 561 make contact at both ends of the bulb body rather than through a base, which is a defining characteristic of that form factor and relevant to physical fitment in the dome light housing.
The 1004 bulb is specified for the 1968-1970 Javelin. It uses a BAY15d bayonet base and carries a dual-filament design rated at 12V with a 21/5W output, meaning the two filaments operate at different wattages.
The 1004 is noted as a variant of the 1157, a widely used automotive bulb. Despite this relationship, the two are not identical, and substitution between them warrants verification of base and filament compatibility before use.
The 1971 Javelin is the only model year in these specifications to use the 158 bulb in the dome light position. The 158 is a T10 miniature wedge bulb rated at 12V and 3W, making it significantly lower in wattage than the other two types listed.
The three bulb types in these specifications, 561, 158, and 1004, each use a different base configuration: end-cap, wedge, and bayonet, respectively. These base types are physically incompatible with one another, so cross-year substitution is not possible without a housing change.
The shift from the 1004 in 1970 to the 158 in 1971, and then to the 561 in 1972, reflects three consecutive changes in dome light bulb specification across the Javelin's later production years, each involving a different base type.