Ford Gran Torino Map Light Bulb Size

The Ford Gran Torino map light requires a 1003 bulb size for proper installation and function within the interior lighting system. Data for the specific component covers the range from 1972 to 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
1972-1976	1003

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1003

Other Locations

Additional Notes

The Ford Gran Torino uses the 1003 bulb for its map light across the 1972-1976 model years.
The 1003 is an ANSI-standardized bulb type, meaning its physical and electrical specifications are governed by a recognized North American standard shared across the US and Canada.
This bulb operates on a 12-volt electrical system, which is consistent with standard automotive DC voltage found in passenger vehicles of this era.
At 21 watts, the 1003 is a relatively modest output bulb, typical of interior courtesy and map lighting applications where prolonged use and low heat output are practical considerations.
The 1003 uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, as opposed to the dual-contact BA15d variant. These two base types are not interchangeable despite sharing the same 15mm collar width.
As a single-filament bulb, the 1003 serves one switching function only, distinguishing it from dual-filament types used in applications such as combined stop and tail lighting.