Ford Mainline Map Light Bulb Size

The Ford Mainline map light requires bulb size 67 or 63 depending on the specific version of the component installed in the vehicle. Data for the bulb sizes covers the range from 1953 to 1956.

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
1956	67
1953-1955	63

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 8W.	67
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 0.63W.	63

Other Locations

Additional Notes

The Ford Mainline map light draws from two ANSI-standard bulb types across its 1953-1956 model years: the 63 and the 67, both rated for 12-volt electrical systems.
The 63 bulb, fitted to the 1953-1955 Ford Mainline, uses a BA9s base, which is a miniature single-pin bayonet fitting commonly associated with low-intensity interior lighting applications.
At 0.63 watts, the 63 bulb represents a very low power draw, consistent with its role as a small courtesy or map light source rather than a high-output lamp.
The 1956 Ford Mainline uses the 67 bulb, which carries a BA15s bayonet base. This is a larger single-contact bayonet fitting compared to the BA9s found on the 63 bulb.
The 67 bulb is rated at 12V and 8W, making it significantly higher in wattage than the 63 bulb used in earlier Mainline model years.
The 67 is described as a lower wattage variant of the 1156 bulb. Both share the BA15s base, but the 1156 operates at a higher wattage, meaning the two are not directly interchangeable despite the shared base type.
The base type change between the 63 (BA9s) and the 67 (BA15s) across the 1955-1956 model year transition indicates a physical socket incompatibility, as the two fittings are mechanically distinct and non-interchangeable.