Dodge Wm300 Pickup Dome Light Bulb Size

The Dodge Wm300 Pickup dome light requires bulb size 1003 or 1004 depending on the specific configuration of the interior lighting system. Data for the lighting components covers the range from 1967 to 1968.

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
1968	1003
1967	1004

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1004

Other Locations

Additional Notes

The 1003 bulb is an ANSI-standard single-filament type rated at 12V and 21W, fitted with a BA15s bayonet base. The BA15s base has a single contact pin, which physically prevents it from accepting dual-filament bulbs.
The 1004 bulb is an ANSI-standard dual-filament type rated at 12V with two wattage levels, 21W and 5W, fitted with a BAY15d bayonet base. The BAY15d base uses two offset pins to ensure correct polarity orientation during installation.
The 1004 is noted as a variant of the 1157, a widely used automotive bulb. Despite this relationship, the two are not always interchangeable, as physical base tolerances and circuit requirements can differ between applications.
The Dodge WM300 Pickup used the 1003 bulb for the dome light in 1968 and the 1004 bulb in 1967. These are distinct bulb types with different base designs, filament counts, and wattage profiles.
Because the 1003 and 1004 use different bayonet base standards, BA15s and BAY15d respectively, the two bulbs are not interchangeable with each other. Attempting to fit one in a socket designed for the other is not possible without modification.