Ford Explorer Turn Signal Bulb Size

Additional Notes

• The T25 wedge base is the most frequently specified front turn signal format across the Ford Explorer's production history, appearing in dual-filament configurations rated at 12V, 27W/7W across the 3157, 3157NA, 3457, 3457NA, and 3757NA bulb types.
• The "NA" suffix in bulb designations such as 3157NA, 3457NA, and 3757NA indicates natural amber glass, meaning the lens color is built into the bulb itself rather than relying on an amber housing or lens cover.
• The Ford Explorer (front turn signal) transitioned from the 3157NA to the 3457NA between the 2004 and 2006 model years, and later shifted from the 3457NA to the 3757NA between the 2015 and 2016 model years.
• The 3457 and 3757NA bulbs share the same T25 wedge base and dual-filament design but differ in whether the glass is clear or natural amber, making them physically interchangeable in socket terms while producing different light color output.
• The rear turn signal position shows considerably more bulb variety than the front, with seven distinct bulb types specified across the Explorer's model range, including T25, T20, BAY15d bayonet, festoon, and specialty halogen formats.
• The 7440NA, a single-filament T20 wedge bulb rated at 12V and 21W, serves as the rear turn signal for the Ford Explorer across the 2013-2019 model years, while the 7440 (clear glass equivalent) is specified for the 2020 and 2023 model years.
• The 12275 is a Philips part number rather than an ANSI standard designation, indicating a proprietary halogen bulb used in the 2011-2012 Explorer rear turn signal that does not share a standardized cross-reference code with other bulbs in the specifications.
• The 2456 is classified as a festoon bulb, a format that differs structurally from wedge and bayonet types, as it seats by compression between two end caps rather than inserting into a socket, and it is specified for the 1997-1999 Explorer rear turn signal.
• The 2356 uses a BAY15d bayonet base, a two-pin offset base type that is not interchangeable with wedge or festoon formats, and it appears in the rear turn signal position for the 1996 and 2000 model years.
• The 3156, specified for the 1995 Explorer rear turn signal, is a single-filament T25 wedge bulb rated at 27W, distinguishing it from the dual-filament 3157 used in adjacent model years despite sharing the same base type and voltage rating.