GMC K1500 Suburban Headlight Bulb Size

Additional Notes

• The GMC K1500 Suburban's headlight specifications span the 1979-1999 model years, covering three distinct sealed beam formats alongside halogen capsule options introduced in the 1992-1999 range.
• The H6054 is the most frequently specified bulb across these specifications, appearing in both high beam and low beam positions from 1981 through 1999. It is a 5x7-inch rectangular sealed beam unit operating at 12V, in which the entire lens-and-reflector assembly is replaced as one piece rather than a separate inner bulb.
• The 1979-1980 model years used the H6024, a 7-inch round sealed beam unit at 12V. Like all sealed beam types in these specifications, the full unit is replaced rather than an individual bulb.
• For the 1982-1986 four-headlamp configuration, the high beam position used the H4651, a 4x6-inch rectangular sealed beam unit at 12V. The low beam position in that same configuration alternated between the H4656 and H4652 depending on the year, both of which share the same 4x6-inch rectangular sealed beam format at 12V.
• The 9005 and 9006 are single-filament halogen capsule bulbs used in the 1992-1999 model years when the vehicle was equipped with halogen capsule headlamps rather than sealed beams. Unlike sealed beam units, these bulbs are replaceable without disturbing the headlamp housing.
• The 9005 handles the high beam function and draws 65W at 12V through a P20d base, while the 9006 handles the low beam function at 55W through a P22d base. The two bulbs use different base types and are not interchangeable with each other despite their similar appearance.
• Vehicles from 1992-1999 required confirmation of headlamp type before bulb selection, as sealed beam units (H6054) and halogen capsule bulbs (9005 or 9006) were both valid fitments for those years and are not cross-compatible.
• All bulb types listed across these specifications conform to ANSI standards applicable in both the United States and Canada, indicating standardized physical and electrical characteristics across manufacturers for each designated size.