GMC Jimmy Headlight Bulb Size

Additional Notes

• The H6054 is the most frequently specified bulb type across the GMC Jimmy's headlight history, covering both high and low beam positions in the 2-headlamp configuration from 1981 through 1994. It is a 5x7-inch rectangular sealed beam unit operating at 12V, conforming to ANSI standards for the US and Canadian markets. As a sealed beam design, the entire unit is replaced rather than an internal bulb.
• The GMC Jimmy (1995-1997) with sealed beam headlamps uses the H4666, a rectangular sealed beam unit rated at 12V, for both high and low beam positions. The same unit serves both functions because the H4666 is a dual-function sealed beam, unlike the separate high and low beam bulbs used in halogen capsule configurations of the same years.
• For 1995-1997 models equipped with halogen capsule headlamps, the high beam position takes a 9005 and the low beam position takes a 9006. These are distinct, non-interchangeable bulbs despite their similar appearance. The 9005 operates at 65W with a P20d base, while the 9006 operates at 55W with a P22d base. The differing wattages and base types mean one cannot be substituted for the other.
• The 4-headlamp configuration present on the GMC Jimmy from 1982 through 1991 introduces additional fitment distinctions. High beam positions in that system used H4651 (1982-1988) or H4701 (1989-1991), while low beam positions used H4656 (1982-1988, excluding 1984) or H4703 (1989-1991). The 1984 model year is a specific exception, specifying H4652 rather than H4656 for the low beam in the 4-headlamp system.
• The H4651 and H4656 are both 4x6-inch rectangular sealed beam units, as is the H4652, which the specifications describe as a variant of the H4651. Despite their physical similarity, these units are designated separately by ANSI standards and are not listed as interchangeable within the specifications.
• The 1970-1972 GMC Jimmy used 4-inch square sealed beam units. The H5001 served the high beam and the H5006, a 5.75-inch round sealed beam unit, served the low beam. This pairing of a square high beam unit with a round low beam unit reflects the 4-headlamp sealed beam system common to that era, where different physical formats were used for each beam function.
• From 1973 through 1980, both high and low beam positions are served by the H6024, a 7-inch round sealed beam unit rated at 12V. This single-unit-per-position arrangement indicates a 2-headlamp system for those years, contrasting with the dual-unit-per-side 4-headlamp configurations that appear in later model years.
• All bulb and sealed beam types listed across the full model range conform to ANSI standards applicable to the US and Canadian markets. Every unit in the specifications operates at 12V, consistent with standard automotive electrical systems of those production years.