Ford Explorer Parking Light Bulb Size

Additional Notes

• The front parking light specifications for the Ford Explorer span model years 1991 through 2019, covering four distinct bulb sizes across that range: 3157, 3157NA, 3457, 3457NA, and 3757NA.
• The 3157NA bulb is the most widely specified across this range, covering the Ford Explorer from 1995 through 2005, with the exception of a mid-production change in 2004. It is an ANSI-standard dual-filament T25 wedge bulb rated at 12V with a 27W/7W filament configuration, and features natural amber glass rather than a clear envelope.
• The 3457NA shares the same T25 wedge form factor, 12V operating voltage, and 27W/7W dual-filament rating as the 3157NA. The two types differ in their internal electrical configuration, which affects compatibility despite their physical similarity.
• The 2004 Ford Explorer underwent a mid-year bulb change on March 1, 2004. Units produced before that date used the 3157NA, while units produced from that date onward used the 3457NA. This production-date distinction makes year alone insufficient for confirming the correct fitment on 2004 models.
• The 3457NA was specified for model years 2006 through 2010, following the mid-2004 transition away from the 3157NA.
• The 3457 bulb, which shares the same wattage and form factor as the 3457NA but lacks the natural amber glass coating, was specified for model years 2011 through 2015.
• The 3757NA was specified for model years 2016 through 2019. Unlike the other bulbs in these specifications, no wattage rating is listed for the 3757NA, though it shares the T25 wedge form factor and natural amber glass construction at 12V.
• The "NA" suffix across the 3157NA, 3457NA, and 3757NA designations indicates natural amber glass, meaning the amber color is produced by the glass itself rather than by a painted or coated clear bulb. This distinction is relevant when sourcing replacements, as a clear-glass equivalent would not replicate the original amber output.
• All five bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada, and all use the T25 wedge base, which is a common automotive base type that does not require a socket twist to install.
• The dual-filament construction present in all listed bulbs means each serves two lighting functions from a single unit. In a parking light application, the lower 7W filament typically handles the steady parking or position light function, while the higher 27W filament handles a secondary function such as turn signaling.