Mack Mid-Liner CS Series Headlight Bulb Size

Additional Notes

• The Mack Mid-Liner CS Series used three distinct headlamp configurations across the 1986-1997 model years: a 2-round-headlamp setup, a 4-rectangular-headlamp setup, and a 4-round-headlamp setup. The correct bulb size is determined by which of these configurations is present on the vehicle, not by model year alone.
• All six bulb types specified for the Mid-Liner CS Series are ANSI-standard sealed beam units rated at 12V. Sealed beam units house the filament, reflector, and lens as a single fused assembly, meaning the entire unit is replaced rather than an internal bulb.
• The H6024 is a 7-inch round sealed beam that serves as both the high beam and low beam in the 2-round-headlamp configuration. A single bulb type covering both functions is a characteristic of certain sealed beam designs where beam pattern is controlled by filament position rather than a separate unit.
• The 4-round-headlamp configuration uses the H5001 for high beam and the H5006 for low beam. The H5001 is a 4-inch square sealed beam, while the H5006 is a 5.75-inch round sealed beam, meaning these two positions are not interchangeable with each other despite being part of the same headlamp system.
• The 4-rectangular-headlamp configuration uses 4x6-inch sealed beam units across all positions, but the specific type varies by function and year. The H4651 is specified for high beam throughout 1986-1997, while the low beam position uses either the H4656 or the H4652 depending on the model year.
• The H4652 is described as a variant of the H4651, both being 4x6-inch rectangular sealed beam units. Despite their physical similarity, they are designated for different beam functions and are not listed as interchangeable within these specifications.
• The low beam rectangular bulb for the 4-rectangular-headlamp configuration is the H4656 for 1986-1993 and 1997, and the H4652 for 1994-1996, with 1986 also using the H4652. These are distinct part numbers within the same physical format and are not cross-listed as substitutes for one another in the specifications.
• All bulb types across both the high beam and low beam specifications for the Mack Mid-Liner CS Series conform to ANSI standards applicable in both the United States and Canada, indicating regulatory compliance across both markets for the full 1986-1997 span covered.