Ram 4500 Turn Signal Bulb Size

The Ram 4500 front turn signal bulb uses a 3157NA or 3157 size bulb for this model. The replacement chart covers vehicle production spanning 2011 to 2018 with corresponding bulb size specifications.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Front Turn Signal

Years	Bulb Size
2013-2018	3157NA (Without Projector-Type Headlamps)
2011-2012	3157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25), natural amber glass. 12V, 27W/7W.	3157NA
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157

Other Locations

Additional Notes

The 3157NA is the most frequently specified front turn signal bulb for the Ram 4500, appearing across the 2013-2018 model years when the vehicle is equipped without projector-type headlamps.
The 3157NA is a dual-filament T25 wedge bulb rated at 12V with a 27W high filament and a 7W low filament, conforming to ANSI standards recognized in both the United States and Canada.
The distinguishing feature of the 3157NA over the standard 3157 is its natural amber glass envelope, which produces an amber-colored output without relying on a separate amber lens.
The 3157 shares the same T25 wedge form factor, dual-filament design, 12V rating, and 27W/7W power draw as the 3157NA, differing only in that its glass is clear rather than amber-tinted.
The Ram 4500 (2011-2012) uses the 3157 for the front turn signal position, while the 2013-2018 model years with the same non-projector headlamp configuration use the 3157NA instead.
Because the 3157 and 3157NA share the same T25 wedge base and electrical ratings, they are physically interchangeable, but substituting a clear 3157 for a 3157NA may affect the amber color output if the housing lens is also clear.
The front turn signal specification for the 2013-2018 Ram 4500 carries a conditional fitment note, as the 3157NA applies only to vehicles without projector-type headlamps.