Seagrave Fire Apparatus T headlight bulbs utilize H4651 size for high beam and H4656 or H4652 sizes for low beam applications. The replacement chart covers 1993 to 2006 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Seagrave Fire Apparatus T relies exclusively on ANSI-standard sealed beam units across all listed model years, with the H4651, H4656, and H4652 types accounting for every headlight position in the specifications.
All three bulb types share the same 4x6-inch rectangular sealed beam format and operate at 12V. Because the light source is integral to the lens and reflector assembly, the entire unit is replaced rather than an internal bulb.
The H4651 serves as the high beam headlight for the Seagrave Fire Apparatus T across all listed years, from 1993 through 2006, with no variation across that span.
The H4656 is the predominant low beam unit, covering the majority of listed model years. The H4652, described as a variant of the H4651, fills the low beam position for the 1993-1995 and 2002 model years instead.
The H4652 is a variant of the H4651 within the same 4x6-inch rectangular sealed beam family. Despite the physical similarity, the two types are not confirmed as interchangeable, and the specifications assign them to distinct positions and years.
The low beam position is the only location where bulb type variation occurs across model years. Selecting the correct type for a specific year requires referencing the year-by-year data, as the H4652 and H4656 are not used interchangeably across all years.