Ford Aerostar Tail Light Bulb Size

Additional Notes

• The Ford Aerostar tail light specifications span the 1986-1997 model years and reference three distinct bulb types: 1157, 2357, and 3457.
• The 1157 bulb is a dual-filament type with a BAY15d bayonet base, rated at 12V with filaments drawing 21W and 5W respectively. It follows the ANSI standard applicable in both the US and Canada.
• The 2357 bulb shares the same BAY15d bayonet base as the 1157 and is also a dual-filament ANSI-standard type, but its filaments are rated at 26.9W and 8W, making it a higher-output variant of the 1157.
• Because the 1157 and 2357 share the BAY15d bayonet base, they are physically compatible in terms of socket fitment, though their wattage ratings differ. Substituting one for the other may affect brightness output.
• The 3457 is a dual-filament wedge bulb of the T25 type, rated at 12V with filaments at 27W and 7W. Unlike the 1157 and 2357, it uses a wedge base rather than a bayonet base, making it physically incompatible with sockets designed for BAY15d bulbs.
• The Ford Aerostar used the 1157 bulb for the 1986-1989 model years in the tail light position.
• The 2357 bulb was specified for the 1990-1996 model years, representing the longest continuous bulb fitment period across the Aerostar's production run covered in these specifications.
• The 1997 model year specifies the 3457 wedge bulb, which differs in base type from all prior Aerostar tail light bulbs listed, indicating a socket change for that year.
• All three bulb types conform to ANSI standards recognized in both the US and Canada, meaning they are sourced from a standardized specification rather than a proprietary or regional format.
• The dual-filament design present in all three bulb types allows a single bulb to serve two lighting functions, typically combining a lower-intensity running light filament with a higher-intensity brake or turn signal filament.