Ram 2500 Turn Signal Bulb Size

Additional Notes

• Three bulb families appear across the Ram 2500 turn signal specifications: the T20 wedge base (7443 and 7444NA) and the T25 wedge base (3157, 3157NA, 3057, and 3057NA). T20 and T25 designations refer to the outer width of the wedge base, meaning bulbs from these two families are not physically interchangeable with each other despite sharing a dual-filament design.
• The 3157 and 3057 are both T25 dual-filament wedge bulbs rated at 12V, 27W/7W, and they share the same wattage output. However, the 3057 uses an asymmetric filament arrangement compared to the 3157, which means the two are not drop-in replacements for each other even though their base size matches.
• The "NA" suffix on bulb types such as 7444NA and 3157NA denotes natural amber glass. This coloring is built into the glass envelope itself rather than applied as a coating, producing the amber signal color without relying on a colored lens.
• The 7443 and 7444NA are both T20 wedge bulbs rated at 12V, 21W/5W. The sole difference between them is the amber glass of the 7444NA. In the Ram 2500 (2024), the front and rear turn signals use different bulbs from this pair, with the 7443 specified for both positions, while the 2023 rear position calls for the 7444NA.
• For the Ram 2500 (2011-2012), the front turn signal fitment depends on headlamp count. The 2-headlamp configuration uses the 3157 with a clear glass envelope, while the 4-headlamp configuration uses the 3157NA with natural amber glass.
• The 2019-2020 front turn signal position specifies the 7444NA only on vehicles with halogen capsule headlamps, while the rear turn signal for those same years specifies the clear-glass 3157 under the same headlamp condition. This means front and rear positions on the same vehicle use bulbs from different base families during that period.
• All bulb types listed in these specifications conform to ANSI standards applicable in both the United States and Canada, indicating consistent part availability across both markets.
• The 2013-2018 front turn signal positions consistently specify the 3157NA, while the corresponding rear positions specify the 3057 for the same years. Because the 3057 and 3157 are not interchangeable, using a rear bulb in a front socket or vice versa during that period would result in an incorrect fitment.