Ford F-250 Turn Signal Bulb Size

Additional Notes

• The Ford F-250 front and rear turn signal specifications span model years 1953 through 1999, covering a total of ten distinct bulb types across both positions.
• The 3157 is the most widely used bulb type in these specifications, appearing in both the front and rear turn signal positions for the 1988-1999 model years, with the exception of 1997-1998 front positions, which use the 3157NA variant. The 3157 is a dual-filament T25 wedge bulb rated at 12V with a 27W high-filament and 7W low-filament output.
• The 3157NA differs from the standard 3157 solely in its natural amber glass envelope, which produces an amber-colored output without relying on a colored lens. Both share identical electrical ratings of 12V, 27W/7W.
• The 1157 is the second most prevalent bulb type in these specifications, serving both front and rear positions across the 1982-1987 model years, as well as the rear position from 1973 through 1981. It uses a BAY15d bayonet base and operates at 12V with a 21W high-filament and 5W low-filament output.
• The 1157NA and 1034NA are natural amber glass variants of the 1157, sharing its BAY15d bayonet base and 12V, 21W/5W ratings. The front turn signal position uses the 1034NA for 1974-1976 and 1981, and the 1157NA for 1973 and 1977.
• Because the 1034NA is described as a variant of the 1157 and shares its base type and electrical ratings, physical fitment to a BAY15d socket is consistent across these variants, though the amber glass coating affects light color output.
• The 1156 is a single-filament bulb with a BA15s bayonet base rated at 12V and 21W. It appears in both front and rear positions across multiple model years from 1958 through 1968, and its single-filament design contrasts with the dual-filament 1157 used in later years.
• The 199 is listed as a variant of the 1156, sharing its BA15s base and 12V, 21W single-filament rating. It is not interchangeable in function with dual-filament types such as the 1157, despite fitting the same base style as the 1156 and 1141.
• The 198 bulb, specified for both front and rear positions in 1969-1972, is a miniature T5 wedge type rated at only 12V and 2W, making it substantially lower in output than all other bulb types listed in these specifications.
• The 1129, used in both front and rear positions for 1953-1955, is a dual-filament bulb with a BAY15d bayonet base and is described as a variant of the 1157. Its 12V, 21W/5W ratings match those of the 1157 family, though it is a distinct ANSI part number.