Ford Aerostar High Beam Indicator Bulb Size

Additional Notes

• The Ford Aerostar high beam indicator uses two distinct bulb sizes across its production run: the 194 and the 37, both of which are ANSI-standard miniature wedge bulbs rated for 12-volt systems.
• The 194 is a T10 wedge bulb rated at 3.78 watts, while the 37 is a T5 wedge bulb rated at 1 watt, making the two types neither physically nor electrically interchangeable despite sharing the same voltage rating.
• The T5 and T10 designations refer to the bulb's tubular envelope width in units of one-eighth of an inch, meaning the T10 body is notably wider than the T5 body.
• The bulb size 37 applies to the Ford Aerostar across 1986-1992, 1995, and 1996, representing the majority of model years covered in the specifications.
• The bulb size 194 applies to 1994 and 1997, as well as to 1993 models without a Digital Instrument Cluster.
• The 1993 Ford Aerostar is the only model year in the specifications where the correct bulb size depends on instrument cluster configuration, with the 37 specified for vehicles equipped with a Digital Instrument Cluster and the 194 specified for those without.
• Because the 1993 model year carries a configuration-dependent fitment, confirming the instrument cluster type before selecting a replacement bulb is relevant to that year specifically.
• The wattage difference between the two bulb types is significant: the 194 draws approximately 3.78 times more power than the 37, which reflects a fundamental difference in filament design rather than a minor variation.