Peterbilt 265 Headlight Bulb Size

Additional Notes

• The Peterbilt 265 (1988-1994) accommodates four distinct headlamp configurations across its model range: two rectangular headlamps, halogen capsule headlamps, four rectangular headlamps, and four round headlamps. Each configuration requires a specific set of bulb sizes for high and low beam functions.
• 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 beam and low beam bulb in the two-rectangular-headlamp configuration, meaning a single bulb type covers both functions on that fitment.
• The 9004 is the only non-sealed-beam bulb type in these specifications. It is a dual-filament halogen bulb rated at 12V with outputs of 65W on high beam and 45W on low beam, using a P29t base. Its dual-filament design allows one bulb to handle both high and low beam duties in the halogen capsule headlamp configuration.
• Sealed beam units such as the H4651, H4652, H4656, H5001, and H5006 are not serviceable at the bulb level. When a sealed beam fails, the entire unit requires replacement, as the lens, reflector, and filament are manufactured as a single assembly.
• The four-rectangular-headlamp configuration uses different bulb sizes for high and low beams. The H4651 handles high beam duty, while the low beam position is filled by either the H4656 or H4652 depending on the model year, both of which are 4x6-inch rectangular sealed beam units operating at 12V.
• The H4652 is specified as a variant of the H4651 within the 4x6-inch rectangular sealed beam family. Despite their shared physical format, the two are not listed interchangeably within the same model year, and substituting one for the other without confirming fitment compatibility is not supported by these specifications.
• The four-round-headlamp configuration uses the H5001 for high beam and the H5006 for low beam across all years covered. The H5001 is a 4-inch square sealed beam unit, while the H5006 is a 5.75-inch round sealed beam unit, reflecting a difference in physical size between the high and low beam positions in that configuration.
• All bulb types listed across both high and low beam positions operate at 12V and conform to ANSI standards applicable in the US and Canada, indicating a consistent electrical system voltage requirement throughout the Peterbilt 265 headlamp specifications for the 1988-1994 period.