Chevrolet Colorado Brake Bulb Size

Additional Notes

• The Chevrolet Colorado uses two distinct brake bulb types across its production years: the 7443 for 2015-2024 and the 3057 for 2004-2012. These two bulbs are not interchangeable, as they differ in both physical size and wattage output.
• The 7443 is a dual-filament wedge bulb rated at 12V with a high filament of 21W and a low filament of 5W. It follows the T20 wedge form factor and meets ANSI standards for the US and Canadian markets.
• The 3057 is also a dual-filament wedge bulb operating at 12V, but it carries a higher wattage rating of 27W on the high filament and 7W on the low filament. Its T25 form factor is physically larger than the T20 used in the 7443.
• The dual-filament design of both the 7443 and 3057 serves the brake light circuit by using the high-wattage filament for braking signals and the lower-wattage filament for tail light or running light functions within the same housing.
• The Center High Mount Stop Light (CHMSL) on the Chevrolet Colorado also follows a generational split, using the 921 bulb for 2015-2024 and the 912 bulb for 2004-2012.
• Both the 921 and 912 are single-filament T15 wedge bulbs operating at 12V. The 912 is a lower-wattage variant of the 921, rated at 12W compared to the 921's 16W, and the two are not rated as direct replacements for each other despite sharing the same T15 form factor.
• The T15 wedge base shared by the 921 and 912 is physically smaller than the T20 and T25 bases used in the main brake light positions, making cross-position substitution between the CHMSL and the brake lights physically incompatible.
• All four bulb types specified across the Colorado's brake lighting system conform to ANSI standards applicable in both the United States and Canada.