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Current textSource: eCFR

§ 393.28 Wiring systems.

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

eCFR (current) ↗
What changedOct. 1, 1996 wording → Oct. 1, 2005 wording (current)+62 added−152 removedHide

(a)Electrical The wiring shall—
(1) Bebe so installed thatand connectionsmaintained areto protectedconform fromto weather,SAE abrasionJ1292—Automobile, road splashTruck, greaseTruck-Tractor, oilTrailer, fuel and chafing;
(2)Motor BeCoach grouped togetherWiring, whenOctober possible1981, andexcept protectedthe byjumper nonconductivecable tape,plug braid,and orreceptacle otherneed coveringnot capableconform ofto withstandingSAE severeJ560. abrasionThe orreference shall be protected by being enclosed in a sheath or tube;
(3) Be properly supported in a manner to preventSAE chafing;
(4)J1292 Notshall benot so located as to be likelyconstrued to berequire charred,circuit overheated,protection oron enmeshedtrailers. in moving parts;
(5)See Not§ have terminals or splices located above the fuel tank except for the fuel sender wiring and terminal; and
(6) Be protected when passing through holes in metal by a grommet, or other means, or the wiring shall be encased in a protective covering393.
7(b) Thefor completeinformation wiringon systemthe includingincorporation lamps,by junctionreference boxes, receptacle boxes, conduit and fittingsavailability mustof bethis weather resistantdocument.
(c) Harness connections shall be accomplished by a mechanical means.
[5370 FR 4939748047, DecAug. 715, 19882005]

49 CFR § 393.28 — Wiring systems.. Text current through October 22, 2026. This wording effective October 1, 2005 to present. Source: eCFR (current), https://www.ecfr.gov/current/title-49/section-393.28. Retrieved from FMCSR.com, https://fmcsr.com/reg/393.28, on October 26, 2026. Unofficial compilation; verify against the official source.

Electrical wiring shall be installed and maintained to conform to SAE J1292—Automobile, Truck, Truck-Tractor, Trailer, and Motor Coach Wiring, October 1981, except the jumper cable plug and receptacle need not conform to SAE J560. The reference to SAE J1292 shall not be construed to require circuit protection on trailers. (See § 393.7(b) for information on the incorporation by reference and availability of this document.)

[70 FR 48047, 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 48047, Aug. 15, 2005]
  2. Oct. 1, 1996 → Oct. 1, 2005annual editions 1996–2004
    [53 FR 49397, Dec. 7, 1988]

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. Set a case date in the header to read any earlier wording.