American Motors Ambassador Dome Light Bulb Size

The American Motors Ambassador dome light utilizes bulb sizes 561, 158, 562, 1004, and 1003 depending on the specific production period for the interior lighting component. Available data covers the span from 1958 through 1974 for the various configurations listed in the records.

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	562
1960-1967	1004
1958-1959	1003

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). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	562
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1004
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003

Other Locations

Additional Notes

The American Motors Ambassador dome light specifications cover model years 1958 through 1974, spanning four distinct bulb types across that period.
The 1004 bulb is the most frequently specified type in these records, appearing across the 1960-1967 model years. It is a dual-filament bulb with a BAY15d bayonet base, rated at 12V and 21/5W, and is a variant of the widely known 1157 bulb.
The 1003 bulb, used in the 1958-1959 Ambassador, shares the same 12V operating voltage as the 1004 but differs in that it is a single-filament design with a BA15s bayonet base, rated at 21W. The BA15s base is not interchangeable with the BAY15d base of the 1004, as the pin alignment differs between the two bayonet standards.
The 562 bulb, specified for the 1968-1970 Ambassador, is a festoon-type bulb with end-cap contacts, rated at 12V and 12W. Festoon bulbs make contact at both ends rather than through a base, which is a fundamentally different mounting method from the bayonet-base bulbs used in earlier model years.
The 561 bulb, specified for the 1972-1974 Ambassador, shares the same festoon form factor, 44mm length, end-cap contact design, and 12V/12W rating as the 562. Despite these similarities, the 561 and 562 carry separate ANSI designations and are not confirmed as interchangeable within these specifications.
The 1971 American Motors Ambassador dome light uses the 158 bulb, a miniature wedge-type (T10) bulb rated at 12V and 3W. At 3W, it operates at a significantly lower wattage than any other bulb type listed across these model years.
The T10 wedge base of the 158 bulb is physically incompatible with the festoon sockets used for the 561 and 562 bulbs, and equally incompatible with the bayonet sockets used for the 1003 and 1004 bulbs.
All five bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada.