The GMC C15 Suburban headlight bulb specifications include H6024 and H5001 sizes for high beam applications, along with H6024 and H5006 sizes for low beam functions. The replacement chart covers vehicle production years spanning 1967 to 1978 with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The two bulb types present across the GMC C15 Suburban headlight specifications are the H6024 and the sealed beam pairing of H5001 and H5006, all operating at 12V and conforming to ANSI standards recognized in both the United States and Canada.
The H6024 is a 7-inch round sealed beam unit. It serves as both the high beam and low beam headlight for the 1973-1978 model years, meaning a single bulb type covers both functions across those years.
For the 1967-1972 model years, the high beam and low beam positions use different sealed beam units. The high beam position takes the H5001, a 4-inch square sealed beam, while the low beam position takes the H5006, a 5.75-inch round sealed beam.
All three bulb types, the H6024, H5001, and H5006, are sealed beam units in which the lens, reflector, and filament form a single assembly. When a filament fails, the entire unit requires replacement rather than an internal bulb swap.
The H5001 and H5006 are not interchangeable with each other despite both being used on the same 1967-1972 vehicles. Their physical forms differ, with the H5001 being square and the H5006 being round, and they occupy separate positions in the headlight assembly.
The H6024 and H5001 are also not interchangeable. The H6024 is a 7-inch round unit, while the H5001 is a 4-inch square unit, and the two belong to different generations of the headlight system used on the C15 Suburban.
The transition from the H5001 and H5006 pairing to the H6024 for both beam positions occurred between the 1972 and 1973 model years of the GMC C15 Suburban.