GMC Terrain front turn signal bulbs use 7444NA and 7443NA sizes, while rear turn signal bulbs use 7440 and 3057 sizes. The replacement chart covers 2010 through 2024 model years 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.
The front turn signal on the GMC Terrain uses either the 7444NA or 7443NA bulb across the 2010-2024 model years, depending on the specific year.
Both the 7444NA and 7443NA are dual-filament T20 wedge bulbs rated at 12V with a 21W high filament and a 5W low filament, and both carry natural amber glass as a factory-tinted alternative to clear bulbs with amber housings.
Although the 7444NA and 7443NA share the same T20 wedge base type and identical wattage ratings, they are distinct ANSI part numbers and are not confirmed as interchangeable within these specifications.
The 7444NA is the more frequently specified front turn signal bulb across the Terrain's model range, appearing in 2010, 2011, 2013, 2015-2016, 2018-2021, and 2023-2024.
The 7443NA is specified for the front turn signal in 2012, 2014, and 2017.
The rear turn signal on the GMC Terrain (2010-2017) uses the 3057 bulb, a dual-filament T25 wedge type rated at 12V, 27W/7W, which is physically larger than the T20 bulbs used at the front.
For 2018-2020 rear turn signals, the GMC Terrain specifies the 7440 only on vehicles equipped with HID headlamps, indicating a trim-level or package dependency for that position.
The 7440 is a single-filament T20 wedge bulb rated at 12V and 21W, which differs functionally from the dual-filament 3057 it replaces in HID-equipped models, as it carries no secondary low-power filament.
The T25 base of the 3057 is physically incompatible with T20 sockets, meaning the rear turn signal bulbs from 2010-2017 and those from 2018-2020 (HID) are not interchangeable with each other or with the front position bulbs.
All bulb types listed across both turn signal positions conform to ANSI standards applicable in the United States and Canada.