§FMCSR.com
Current textIn force on Sept. 29, 2025Source: eCFR

§ 393.79 Windshield defrosting and defogging systems.

Current wording, in the annual edition revised as of Oct. 1, 2005.

eCFR as of September 29, 2025 ↗
49 CFR § 393.79 — Windshield defrosting and defogging systems.. Text in force on September 29, 2025. This wording effective October 1, 2005 to present. Source: eCFR as of September 29, 2025, https://www.ecfr.gov/on/2025-09-29/title-49/section-393.79. Retrieved from FMCSR.com, https://fmcsr.com/reg/393.79?asof=2025-09-29, on October 26, 2026. Unofficial compilation; verify against the official source.

(a) Vehicles manufactured on or after December 25, 1968. Each bus, truck, and truck-tractor manufactured on or after December 25, 1968, must have a windshield defrosting and defogging system that meets the requirements of FMVSS No. 103 in effect on the date of manufacture.

(b) Vehicles manufactured before December 25, 1968. Each bus, truck, and truck-tractor shall be equipped with a means for preventing the accumulation of ice, snow, frost, or condensation that could obstruct the driver's view through the windshield while the vehicle is being driven.

[70 FR 48054, Aug. 15, 2005]

Amendment history

2 distinct wordings on file since Oct. 1, 1996
  1. Oct. 1, 2005 → presentannual editions 2005–2016diff vs. previousviewing
    [70 FR 48054, Aug. 15, 2005]
  2. Oct. 1, 1996 → Oct. 1, 2005annual editions 1996–2004

A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.