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SlideInDad's avatar
SlideInDad
Explorer
May 26, 2020

12V wiring Aluminum Cargo Trailer conversion

Been searching for days and haven't found a clear answer on whether or not a 12V system should be grounded to the chassis of a 100% aluminum framed enclosed trailer. Am I better running negative wires back from every light and fan back to the batteries or will the aluminum frame conduct well enough without corrosion?

All my searches regarding grounding aluminum framed trailers talk about vehicle wiring from the truck back for running lights/directionals... This line actually says do not ground to the trailer chassis: Aluminum trailer grounding But my question is for a house 12v system unrelated to the tow vehicle.
  • DrewE's avatar
    DrewE
    Explorer II
    May 26, 2020
    WNYBob wrote:
    I think you have missed the point that there are 2 separate 12v systems in a TT. One is the TV (tow vehicle and the DMV lighting) circuit and the other is the TT. They should not be mixed.


    Both ought to be bonded to the trailer frame, though, regardless of whether that forms the negative return for current or not. For the house electric system, if there is a converter included, I think this is a requirement of the NEC. (Similarly, the 120V ground needs to be bonded to the chassis.)
  • Dusty_R's avatar
    Dusty_R
    Explorer
    May 26, 2020
    There is an anti-oxidizing paste/grease used on aluminum wire. If you do use the aluminum body for the 12v ground be sure to use past/grease on all places where grounding to the body. And do not fasten copper wire to the aluminum body.

    Dusty
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    May 26, 2020
    Poor grounding is a common problem. Keep it corrosion free and use anti corrosion product.
  • WNYBob's avatar
    WNYBob
    Explorer
    May 26, 2020
    I think you have missed the point that there are 2 separate 12v systems in a TT. One is the TV (tow vehicle and the DMV lighting) circuit and the other is the TT. They should not be mixed.
  • opnspaces's avatar
    opnspaces
    Navigator II
    May 26, 2020
    I think most RV's have interior ground wires coming back to the electric panel. You could try reaching out to Jayco or any other manufacturer customer service and ask them how the interior lights are grounded.
  • SlideInDad's avatar
    SlideInDad
    Explorer
    May 26, 2020
    CA Traveler wrote:
    Your link sounds like a concern for corrosion which can become a problem. Good maintained grounding would do the job. 10 ga is likely over kill for the running lights ground especially for LED lights.

    Are you going to use the TV to charge the trailer battery? Regardless I'd ground the 12V interior system including any incoming AC to the trailer.

    Aluminum conductivity would not be a concern for me but long term corrosion can be a issue.


    Trailer house batteries will be charged by solar and a IOTA 45 converter when connected to AC via either a generator or when at home. Exactly what do you mean regarding a well maintained grouding? Cleaning were it grounds to the frame from the batteries frequently?
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    May 26, 2020
    Your link sounds like a concern for corrosion which can become a problem. Good maintained grounding would do the job. 10 ga is likely over kill for the running lights ground especially for LED lights.

    Are you going to use the TV to charge the trailer battery? Regardless I'd ground the 12V interior system including any incoming AC to the trailer.

    Aluminum conductivity would not be a concern for me but long term corrosion can be a issue.

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