Ford Aerostar Courtesy Bulb Size

Additional Notes

• The Ford Aerostar courtesy bulb specifications span the 1986-1997 model years, with six distinct bulb types used across that period: the 194, 168, 912, 89, 97, and 906.
• The T10 wedge form factor is the most frequently represented across the Aerostar's courtesy bulb history, covering the 194, 168, and 906 types, though these three share the same physical base while differing in wattage output.
• The 194 bulb operates at 3.78W and appears in the 1994-1995 and 1997 model years, making it the most recurrent single bulb type in the specifications.
• The 168 bulb operates at 4.9W and is specified for the 1987, 1991, 1993, and 1996 model years. Although it shares the T10 wedge base with the 194, its higher wattage rating means the two types are not directly interchangeable without accounting for that difference.
• The 906 bulb, specified for the 1986 model year, also uses the T10 wedge base but draws 8W, a notably higher load than either the 194 or 168 within the same base family.
• The 912 bulb, used in the 1992 model year, is a T15 wedge type rated at 12V and 12W. It is described as a variant of the 921, and the larger T15 base distinguishes it physically from the T10 wedge bulbs used in other years.
• The 89 and 97 bulbs, specified for the 1990 and 1988-1989 model years respectively, both use the BA15s single-contact bayonet base and share a 13W rating. This base type is physically distinct from the wedge-style bulbs used across the majority of the Aerostar's model range.
• The 89 is noted as a lower wattage variant of the 1156, while the 97 is described as a variant of the 1156. Despite sharing the same wattage figure in these specifications, the two are separate ANSI-designated types and are not listed as interchangeable with each other.
• All six bulb types in the specifications conform to ANSI standards recognized in both the United States and Canada, and all operate on a 12V electrical system consistent with standard automotive applications.
• The variety of bulb bases across the Aerostar's model range, spanning T10 wedge, T15 wedge, and BA15s bayonet types, indicates that courtesy bulb fitment is year-specific and cross-year substitution is not supported by these specifications.