Ram 3500 Turn Signal Bulb Size

Additional Notes

• The front turn signal specifications for the Ram 3500 reference three distinct bulb types across the 2011-2024 model years: the 7444NA, 3157NA, and 3157. All three are dual-filament designs built to ANSI standards for the US and Canadian markets.
• The 7444NA is a T20 wedge bulb rated at 12V with a 21W high filament and 5W low filament. It carries natural amber glass, meaning the housing itself produces the amber signal color rather than relying on a colored lens.
• The 3157NA is a T25 wedge bulb rated at 12V with a 27W high filament and 7W low filament. Like the 7444NA, it uses natural amber glass for color output. It serves as the front turn signal on the Ram 3500 from 2013-2018 in configurations without projector-type headlamps.
• The 3157 and 3057 share the same T25 wedge form and identical 12V, 27W/7W ratings. The 3057 differs from the 3157 in filament orientation, which affects socket compatibility. Despite their similar electrical ratings, the two are not interchangeable due to this physical difference in the wedge base configuration.
• The 1157 rear turn signal bulb used on the 2023-2024 Ram 3500 departs from the wedge-base format used in other positions. It uses a BAY15d bayonet base and is rated at 12V, 21W/5W, making it electrically similar to the 7444NA but physically incompatible due to the different base type.
• Front turn signal fitment on the 2011-2012 Ram 3500 depends on headlamp count. The two-headlamp configuration takes a 3157, while the four-headlamp configuration requires a 3157NA. These two bulbs share the same base and wattage but differ in glass color, so substituting a clear 3157 in a position specified for the 3157NA would alter the color output of the signal.
• The 2019-2020 Ram 3500 front and rear turn signal specifications are conditional on the presence of halogen capsule headlamps, with the front position requiring a 7444NA and the rear requiring a 3157. These are not universal fitments across all trim or equipment configurations for those years.
• The rear turn signal transitions from the 3057 (2013-2018, without projector-type headlamps) to the 3157 (2011-2012) and then to the 1157 (2023-2024), reflecting changes in base type and socket design across the production span covered by these specifications.