Honda Accord Turn Signal Bulb Size

Additional Notes

• The 2057 bulb is the most historically recurring front turn signal fitment across the Honda Accord, appearing in model years 1976-1978 and 1982-1985. It is a dual-filament bulb rated at 12V with a high-intensity filament drawing 26.9W and a low-intensity filament drawing 8W, mounted on a BAY15d bayonet base.
• The 1156 bulb holds the same distinction on the rear turn signal position, covering model years 1976-1978, 1982-1985, and 1990-1991. It is a single-filament bulb with a BA15s bayonet base rated at 12V and 21W under the ANSI standard.
• The 3497, used in the front turn signal position for the 1990-1991 Honda Accord, shares the BA15s bayonet base with the 1156 but is classified as a variant of it rather than a direct equivalent. Despite identical voltage and wattage ratings, the two are distinct ANSI part numbers and are not listed as interchangeable.
• The 7443NA, specified for the 2018 Honda Accord front turn signal, is a dual-filament T20 wedge bulb rated at 12V with filaments drawing 21W and 5W respectively. Its natural amber glass produces color without a painted or coated lens.
• The 7440NA, specified for the 2021 front turn signal, shares the T20 wedge form factor and natural amber glass with the 7443NA but is single-filament, rated at 12V and 21W. The two bulbs differ in filament count, which affects socket compatibility despite their physical similarity.
• The 2021 Honda Accord rear turn signal uses the PY21W bulb exclusively in configurations with halogen lamp headlights. The PY21W follows the ECE standard rather than the ANSI standard, uses a BAU15s bayonet base, and is rated at 12V and 21W. The BAU15s base has an offset pin arrangement that prevents installation of BA15s or BAY15d bulbs in the same socket.
• The 12496 is a Philips/Osram part number rather than an ANSI or ECE designation, and it is rated at 12V for a specialty halogen application. It appears in the rear turn signal position for the 2018-2020 Honda Accord.
• The 2057 is described as a brighter variant of the 1157, and the 3497 is described as a variant of the 1156. In both cases, the variant designation indicates a difference in output or classification that makes substitution with the base part number inadvisable without confirming compatibility.
• The front and rear turn signal positions on the 2018 Honda Accord use different bulb types, with the 7443NA at the front and the 12496 at the rear. The two are not interchangeable due to differences in base type and filament configuration.
• All bulbs listed across both positions operate at 12V, consistent with standard automotive electrical systems. Wattage varies by bulb type and filament count, ranging from the dual-filament 2057 at 26.9W down to the low-intensity filament of the 7443NA at 5W.