Battery wires Black, White, or Red

Discussion in 'Wiring' started by Raycfe, Apr 26, 2021.

  1. Raycfe

    Raycfe Waterford Ct.

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    Oct 3, 2007
    Waterford, Ct
    Most of the popups I have worked will have a white ground wire and a black positive wire. But where does the Red wires come into play.
    Campers I have seen are wired like homes. Its a home on wheels ..... Right.
    Both the AC and DC circuits use the same colors ..... usually Black for power and White for ground.
    But your Tow Vehicle is not a home on wheels and are usually wired differently ........ Black is used a lot as a ground wire and red as a power wire. The equipment that is added to a camper can and usually does use the automobile wire code. The power tongue jack, water pump etc could use this automotive code.
    So if you find a red wire connected to your camper search what it is connected to and you should find it has a black wire instead of white for a ground wire and connect accordingly.
    I try to mark battery wires and even paint the black odd ground wires white and the red black so I can correctly connect them the next time I service/change a battery.
    neighbormike and Sjm9911 like this.
  2. SteveP

    SteveP Well-Known Member Platinum Supporting Member

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    May 21, 2015
    I grew up working on 12 volt automotive systems so I'm partial to red. If I were doing the original wiring on a camper I would use red for the battery positive. I would not use black at all on the 12 volt system to avoid the confusion you're talking about. Blue should only be used for brake system wiring. I would also not use green for any 12 volt circuit wire, green is always reserved for 120 volt AC ground. But it's not a perfect world is it?
    WrkrBee likes this.
  3. jmkay1

    jmkay1 2004 Fleetwood/Coleman Utah

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    Oct 10, 2013
    Northern Virginia
    Geeze I wish I saw this message back when I first got my camper. Hooking up the battery went against everything I was taught. So apparently I was taught car wiring and the science teacher failed to specify there was a difference. Good thing I never replaced something in my house, I’d probably smoke something up or worse. Gosh knows I’ve blown a few fuses in the camper when reversing the polarity in error until I learned my way around the system.
  4. TSQ

    TSQ Active Member

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    Mar 28, 2021
    Niagara Region, ON
    IMHO trailer wiring in general is a disaster. In my new (to me) trailer the DC wiring is a mix of trailer (white=neg, black=pos), industrial (black=neg, white=pos), automotive (black=neg, red=pos), and marine (yellow=neg, red=pos). Plus the converter has a rainbow coming out of it including green (which is internationally recognized as ground) as a DC positive. And this is on a trailer with a 2018 build date.

    The marine industry switched to yellow for DC negative because too many people were electrocuting themselves cutting into black wires thinking they were DC negative only to find out they were AC hot.

    Note that while it is common to ground the negative side of your DC system, the correct way to identify the two wires is "positive" and "negative" (not "ground"). Some higher power DC equipment with metal cases such as battery chargers and inverters also have a separate ground connection. Some older DC systems used a positive ground - a lot of telecom equipment is still 48v DC with a positive ground.

    Likewise, in a single phase North American AC system you have a "hot" (typically black), "neutral" (typically white), and "ground" (typically green or bare). Although the white wire is grounded (at a single point only) it is still a current carrying conductor and not a ground.
    Raycfe likes this.

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