§FMCSR.com
Current textIn force on Dec. 31, 2016Source: annual CFR editions 2005–2016

§ 393.78 Windshield wiping and washing systems.

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

govinfo, 2016 edition ↗
Before Jan. 1, 2017 the record is one snapshot per annual CFR edition, revised as of October 1. This is the 2016 edition's wording. An amendment that took effect between Oct. 1, 2016 and Dec. 31, 2016 would not appear until the next edition, so check the citations below and the Federal Register for exact effective dates.
49 CFR § 393.78 — Windshield wiping and washing systems.. Text in force on December 31, 2016. This wording effective October 1, 2005 to present. Source: govinfo, 2016 edition, https://www.govinfo.gov/app/details/CFR-2016-title49-vol5/CFR-2016-title49-vol5-sec393-78. Retrieved from FMCSR.com, https://fmcsr.com/reg/393.78?asof=2016-12-31, 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 wiping system that meets the requirements of FMVSS No. 104 (S4.1) in effect on the date of manufacture. Each of these vehicles must have a windshield washing system that meets the requirements of FMVSS No. 104 (S4.2.2) in effect on the date of manufacture.

(b) Vehicles manufactured between June 30, 1953, and December 24, 1968. Each truck, truck-tractor, and bus manufactured between June 30, 1953, and December 24, 1968, shall be equipped with a power-driven windshield wiping system with at least two wiper blades, one on each side of the centerline of the windshield. Motor vehicles which depend upon vacuum to operate the windshield wipers, shall have the wiper system constructed and maintained such that the performance of the wipers will not be adversely affected by a change in the intake manifold pressure.

(c) Driveaway-towaway operations. Windshield wiping and washing systems need not be in working condition while a commercial motor vehicle is being towed in a driveaway-towaway operation.

[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.