The Hummer H3 front and rear turn signal bulbs both utilize a 3157 size bulb for proper operation. The replacement chart covers vehicle production spanning 2006 to 2010 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 Hummer H3 uses the 3157 bulb for both front and rear turn signals across all model years from 2006-2010.
The 3157 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
The 3157 is a dual-filament bulb, which means it contains two separate filaments within a single housing, allowing it to serve more than one lighting function.
The bulb operates on a 12-volt electrical system, consistent with standard automotive electrical architecture.
The two filaments in the 3157 are rated at 27 watts and 7 watts respectively, where the higher-wattage filament typically handles the brighter turn signal or brake function and the lower-wattage filament handles a reduced-intensity function such as a parking or running light.
The 3157 belongs to the T25 wedge bulb family, a designation that refers to its base and housing form factor used in automotive lighting sockets.
Because the Hummer H3 uses the same 3157 bulb for both front and rear turn signal positions across all five model years, the front and rear sockets share the same bulb type and are not interchangeable with a single-filament variant without potential loss of function.