Plymouth Valiant Map Light Bulb Size

The Plymouth Valiant map light utilizes bulb sizes 89, 90, and 1004 depending on the specific version of the vehicle. Data for the components covers the range from 1961 through 1976.

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
1969-1976	89
1963-1968	90
1961-1962	1004

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	89
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 13W.	90
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1004

Other Locations

Additional Notes

The Plymouth Valiant map light specifications span the 1961-1976 model years, with three distinct bulb sizes used across that range.
The bulb 89 is an ANSI-standard single-filament type rated at 12V and 13W, fitted with a BA15s bayonet base, and is specified for the Plymouth Valiant from 1969-1976.
The bulb 90 shares the same 12V, 13W rating and BA15s bayonet base as the 89, and is specified for the 1963-1968 model years.
Although the 89 and 90 bulbs share identical voltage, wattage, and base type, they carry different ANSI designations and are listed as separate part numbers, which indicates they are not confirmed as interchangeable within these specifications.
The bulb 1004 is a dual-filament type rated at 12V with a 21/5W output, fitted with a BAY15d bayonet base, and is specified for the 1961-1962 model years.
The BAY15d base used by the 1004 bulb features offset locating pins, which physically prevents it from being substituted with the single-filament BA15s-based bulbs used in later Valiant model years.
The 1004 is described as a variant of the 1157, a widely recognized dual-filament automotive bulb, while the 89 is described as a lower wattage variant of the 1156, a common single-filament type.
The transition from the dual-filament 1004 to the single-filament 90 occurred between the 1962 and 1963 model years, representing a change in both filament count and base type for the map light position.