Ford Aerostar Engine Compartment Light Bulb Size

The Ford Aerostar engine compartment light uses 912 and 906 bulb sizes for the internal illumination component. Available data for the specified vehicle covers the period from 1987 through 1997.

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
1991-1997	912
1990	906
1987	912

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906

Other Locations

Additional Notes

The Ford Aerostar engine compartment light uses the 912 bulb for model years 1987 and 1991-1997, making it the predominant fitment across the production run covered by these specifications.
The 912 is an ANSI-standardized wedge bulb rated at 12 volts and 12 watts, classified under the T15 body type, and is recognized as a variant of the 921 bulb.
The T15 designation refers to the bulb's tubular glass envelope, with the numeric portion indicating its width in eighths of an inch, placing it in a mid-range size category among wedge-base miniature bulbs.
The 1990 Ford Aerostar departs from the otherwise consistent 912 fitment, specifying instead the 906 bulb for the engine compartment light.
The 906 is an ANSI-standardized miniature wedge bulb rated at 12 volts and 8 watts, classified under the T10 body type, making it physically smaller and lower in wattage than the 912.
Because the 906 and 912 differ in both body type and wattage, the two bulbs are not interchangeable, and substituting one for the other in a given model year would result in an incorrect fitment.
Both the 906 and 912 operate on a 12-volt electrical system, which is standard across automotive applications in the United States and Canada, consistent with their ANSI classifications.
The wedge-base construction shared by both bulb types means neither requires a separate metal base or socket pins; the glass envelope itself forms the electrical contact, a design common in low-current automotive lighting positions such as engine compartment illumination.