Cadillac SRX Turn Signal Bulb Size

Cadillac SRX front inner turn signal bulbs use 7443NA or 7444NA sizes, front turn signal bulbs use 7440NA, 7444NA, or 3757NA sizes, and rear turn signal bulbs use 7440 size. The replacement chart covers 2004 to 2016 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.

Front Inner Turn Signal

Years	Bulb Size
2012-2016	7443NA
2011	7444NA
2010	7443NA

Front Turn Signal

Years	Bulb Size
2014-2016	7440NA
2013	7440NA (For vehicle without Headlmaps, Right Hand Rule Of The Road, (Marked E))
2011-2012	7444NA (For vehicle with Headlamps High Intensity Discharge, For vehicle with Headlamps High Intensity Discharge, Right Hand Rule Of Road, Front)
2011-2012	7440NA (For vehicle without Headlmaps, Right Hand Rule Of The Road, (Marked E), For vehicle without Headlamps High Intensity Discharge, For vehicle without Headlamps High Intensity Discharge, Right Hand Rule Of Road, Front)
2010	7440NA
2010	7444NA (For vehicle with Headlamps High Intensity Discharge, For vehicle with Headlamps High Intensity Discharge, Right Hand Rule Of Road, Front)
2004-2009	3757NA

Rear Turn Signal

Years	Bulb Size
2010-2016	7440

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T20), natural amber glass. 12V, 21W/5W.	7443NA
ANSI standard (US & Canada). Dual-filament wedge bulb (T20), natural amber glass. 12V, 21W/5W.	7444NA
ANSI standard (US & Canada). Single-filament wedge bulb (T20), natural amber glass. 12V, 21W.	7440NA
ANSI standard (US & Canada). Dual-filament wedge bulb (T25), natural amber glass. 12V.	3757NA
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440

Other Locations

Additional Notes

The Cadillac SRX turn signal system draws from four distinct bulb types across its production run: the 7443NA, 7444NA, 7440NA, and 3757NA for signaling positions with natural amber glass, and the 7440 for the rear turn signal.
The 7443NA and 7444NA are both dual-filament T20 wedge bulbs rated at 12V, 21W/5W, and both carry ANSI standardization for the US and Canadian markets. Despite their near-identical specifications, they are not the same part number and are not listed as interchangeable within these specifications.
The 7440NA is a single-filament T20 wedge bulb rated at 12V, 21W, with natural amber glass. It shares the T20 wedge base with the 7443NA and 7444NA but carries only one filament, making it functionally distinct from those dual-filament types.
The 3757NA is a T25 wedge bulb, which is a physically larger base format than the T20 used by the 7440NA, 7443NA, and 7444NA. This size difference is relevant to fitment, as T20 and T25 bulbs are not interchangeable.
The Cadillac SRX (2004-2009) front turn signal position uses the 3757NA, while 2010 and later model years use T20-based bulbs. This represents a base format change between generations that affects physical fitment.
For the 2010-2012 front turn signal position, the SRX requires either a 7444NA or a 7440NA depending on whether the vehicle is equipped with High Intensity Discharge headlamps. HID-equipped vehicles use the dual-filament 7444NA, while non-HID vehicles use the single-filament 7440NA.
The 2013-2016 front turn signal position standardizes on the 7440NA without a headlamp-type condition, indicating that the HID-related split fitment no longer applies to those model years.
The front inner turn signal position uses the 7443NA for the 2010 and 2012-2016 model years. The 2011 model year is the sole exception within that range, specifying the 7444NA instead.
The rear turn signal position for the 2010-2016 SRX uses the standard 7440, which lacks the NA natural amber glass designation. Unlike the 7440NA used at the front, this clear-glass version relies on an amber lens or housing to produce the required signal color.
The "Right Hand Rule Of The Road" and "(Marked E)" notations in the front turn signal fitment conditions refer to traffic-side and ECE regulatory distinctions, indicating that certain bulb assignments are specific to vehicles built for right-hand-traffic markets under European-style certification.