Chevrolet R/V Series Headlight Bulb Size

Additional Notes

• The Chevrolet R/V Series headlight specifications across 1987-1991 reflect three distinct headlamp system configurations: a two-lamp rectangular setup, a four-lamp rectangular or round setup, and a halogen capsule system. Each configuration uses a different bulb type for both high and low beam functions, and the correct bulb is determined entirely by which headlamp system is installed on the vehicle.
• The H6054 is a 5x7-inch rectangular sealed beam unit operating at 12V and conforming to ANSI standards for the US and Canadian markets. It serves as both the high and low beam in the two-rectangular-lamp configuration, meaning a single unit handles both functions. The entire assembly is replaced rather than an internal bulb, which is characteristic of sealed beam technology.
• The four-lamp rectangular configurations use separate units for each beam function. The H4701 handles high beam duty while the H4703 handles low beam. Both are 7-inch round sealed beam units operating at 12V, though H4701 is noted as a variant within that form factor. These two units are not interchangeable with each other despite sharing the same physical format.
• The 1987 four-lamp configuration differs from later years in that it uses 4x6-inch rectangular sealed beam units rather than 7-inch round units. The H4651 serves the high beam position and the H4652 serves the low beam position. H4652 is a variant of H4651, and while they share the same physical sealed beam format, they are not interchangeable due to their distinct beam functions.
• The halogen capsule headlamp system, available on the Chevrolet R/V Series in 1990-1991, uses replaceable single-filament bulbs rather than sealed beam assemblies. The 9005 handles the high beam at 65W and the 9006 handles the low beam at 55W. Unlike the sealed beam types, only the internal bulb is replaced when the unit fails.
• The 9005 and 9006 halogen bulbs differ in both wattage and base type. The 9005 uses a P20d base at 65W, while the 9006 uses a P22d base at 55W. The differing base designs physically prevent cross-installation between the two positions, which is a deliberate safety feature of the ANSI standard governing these bulb types.
• The H6054 sealed beam unit appears across all years in the specifications, from 1987 through 1991, in the two-lamp rectangular configuration for both high and low beam positions. Its consistent presence across this span reflects its role as a long-standing ANSI-standardized sealed beam format widely used in North American vehicle lighting.
• All bulb types listed in these specifications conform to ANSI standards applicable to the US and Canadian markets and operate on 12V electrical systems. Sealed beam units in the specifications are not compatible with halogen capsule sockets, and the two system types represent fundamentally different headlamp assembly designs that are not interchangeable at the vehicle level.