Oldsmobile 88 Dome Light Bulb Size

The Oldsmobile 88 dome light requires bulb size 906 or 1004 depending on the specific application. Available data for the bulb sizes covers the range from 1954 to 1999.

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
1996-1999	906
1992-1994	906
1954-1957	1004

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1004

Other Locations

Additional Notes

The Oldsmobile 88 dome light uses two distinct bulb types across its model years: the 906 and the 1004, both conforming to ANSI standards recognized in the US and Canada.
The 906 bulb is a T10 miniature wedge type rated at 12V and 8W, and it serves as the dome light bulb for the Oldsmobile 88 across the 1992-1994 and 1996-1999 model years.
The T10 wedge base on the 906 bulb is a push-in, pinless design, meaning it is retained by friction rather than a locking mechanism, which is a common trait of miniature wedge bulbs in interior lighting applications.
The 1004 bulb is a dual-filament type with a BAY15d bayonet base, rated at 12V with a 21/5W output, and it is specified for the 1954-1957 model years of the Oldsmobile 88.
The BAY15d bayonet base on the 1004 bulb features two offset pins, which physically prevent incorrect installation by ensuring only one rotational orientation is accepted by the socket.
The 1004 bulb is noted as a variant of the 1157, a widely used automotive bulb. Despite this relationship, the two are not directly interchangeable, as differences in filament wattage and base pin positioning can affect fitment and function.
The single-filament 906 and the dual-filament 1004 serve different socket types, meaning the bulbs specified for the 1954-1957 model years are not compatible with the sockets used in the 1992-1999 model years.
The shift from the dual-filament 1004 in mid-1950s models to the single-filament 906 in 1990s models reflects a change in socket and fixture design across those generations of the Oldsmobile 88.