TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

12Volt trunk/Frunk Cable Routing on 3D.

Discussion in 'Model 3' started by M0DEL³, Aug 14, 2018.

  1. M0DEL³

    M0DEL³ Member

    Joined:
    Mar 17, 2016
    Messages:
    169
    Location:
    A
    I have a project goal to add 12Vdc power ports to both the Frunk and Trunk areas. I have seen @Ingineer's videos regarding harvesting the available tap on vcLeft. Was wondering the following:

    Does anyone have experience/insights into optimal cable routing paths to bring 12Vdc to the frunk and trunk areas?
    If one wanted an additional power tap point besides vcLeft is there a 2nd most recommended tap point for a 10amp load?

    In the case of my project, this is for a Dual Motor, to the extent that this influences anyone's routing thoughts.

    As for placement within the trunks my project has flexibility regarding left/right side placement.
    Would greatly appreciate anyone sharing their insights.
     
  2. Ingineer

    Ingineer Electrical Engineer

    Joined:
    Aug 8, 2012
    Messages:
    1,477
    The factory cabling runs down each side just below the rocker trim on the inside of the car. It's easy to remove this and run additional cabling. The lower part of the rear seat is also easy to remove, there are 2 release levers on the front edge middle of each of the main seating positions.

    If you need high-current 12v, such as for an inverter or audio amp, I would tap from the passenger side, under the rear seat. You can't miss the huge red cable. However, this is always hot, so make sure you take steps to not allow your load to discharge the tiny 12v battery in the 3. If it's an amp, then make sure it's turn-on lead gets switched power. Same for an inverter, but if your inverter doesn't have an external switch input, then use a heavy relay (contactor) and drive it from a switched line, such as the one I identified in my videos:




    Also, be sure to use a proper fuse placed as close the the 12v source as possible and installed in a way where it cannot get damaged or pinched by the seat. The DC-DC converter can handle over 150A, so be very careful!
     
    • Informative x 1
  3. BioSehnsucht

    BioSehnsucht Model 3 LR

    Joined:
    Apr 1, 2016
    Messages:
    737
    Location:
    DFW, TX
    Supposedly, the car will switch off current faster than a fuse can react if load is too high (except for the HVDC pyro fuses there are no traditional fuses in the car, it's all electrically controlled current cut offs etc), but personally I would probably still fuse the line anyways out of paranoia and the fact it's easy to do.

    Especially if the wire you're using can't handle the full rated load of the circuit (15A? I don't remember). If the wire is only big enough for 5A or whatever, fuse it to 5A, because the car won't shut it off until it hits the car's defined limit, which will be 10A or whatever later.

    But if you use large enough gauge wiring for everything, and every component can handle it

    edit: I just realized you may have meant to always fuse if taking 12V straight from the source, which is definitely something you should do. But for smaller items even from the 'hitch' connection I would still fuse it.
     
  4. BioSehnsucht

    BioSehnsucht Model 3 LR

    Joined:
    Apr 1, 2016
    Messages:
    737
    Location:
    DFW, TX
    The 'hitch' or whatever connection in the vcleft, it's switched to only be on when the car is "on" right? Do we have any similar options that are always on, besides tapping an existing wire or the 12V battery or DC-DC ?
     
  5. compu85

    compu85 Member

    Joined:
    Jun 7, 2016
    Messages:
    39
    Location:
    Springfield, VA, USA
    Fuses protect the wiring. So if the device you're wiring into VC-L has wiring that's rated for 10A, no additional fuse would be needed. If the add-on has thin wiring, then adding a smaller fuse between VC-L and the device will protect that wire from overheat / fire.

    -J
     

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC