Peterbilt 330 Headlight Bulb Size

Additional Notes

• The 9007 bulb is a dual-filament halogen type that serves both high beam and low beam functions within a single housing. The Peterbilt 330 used this bulb across both beam positions for the 2011-2017 model years, making it the sole headlight bulb type for that period.
• The 9004 bulb is also a dual-filament halogen unit, functioning as both a high beam and low beam source. On the Peterbilt 330, it was specified for halogen capsule headlamp configurations from 1995 through 2009, covering the same beam positions as the 9007 in later years.
• The H6054 is a sealed-beam rectangular halogen unit rated for both high and low beam output. It was specified for 2-rectangular-headlamp configurations on the 330 from 1995 through 2009, serving both beam positions within that single sealed unit.
• The H4651 and H4656 are separate sealed-beam rectangular units designated for high beam and low beam respectively in 4-rectangular-headlamp configurations. These two bulbs are not interchangeable with each other, as each is engineered for a specific beam function.
• In certain years, the low beam position in 4-rectangular-headlamp configurations called for either H4652 or H4656, depending on the model year. These are distinct part numbers and are not cross-compatible, so the correct year must be referenced before selecting a replacement.
• The H5001 and H5006 are round sealed-beam units designated for high beam and low beam positions respectively in 4-round-headlamp configurations. This headlamp style was listed only for the 1995-1997 model years of the Peterbilt 330.
• Because the 330 used up to three different headlamp system types in a single model year, the specific headlamp configuration installed on the vehicle determines which bulb applies. Selecting a bulb by year alone, without confirming the headlamp type, risks an incorrect fitment.
• Sealed-beam units such as the H6054, H4651, H4652, H4656, H5001, and H5006 integrate the reflector, lens, and filament into one non-serviceable assembly. This construction differs from the 9004 and 9007 types, which are replaceable capsule bulbs seated within a separate housing.
• The 9007 and 9004 bulbs share a dual-filament design but use different connector configurations, making them physically non-interchangeable despite their functional similarity. A vehicle specifying one will not accept the other without modification to the socket.
• The 2008 low beam specification for 4-rectangular-headlamp configurations lists the H4652, while the 2009 specification for the same configuration lists the H4656. These are separate part numbers, and the year of the vehicle is the determining factor in selecting the correct low beam sealed-beam unit for that headlamp style.