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How do I get constant 12 volt power from trailer wiring?

Discussion in '2.5 Gen Tundras (2014-2021)' started by RobinElectronics, May 14, 2018.

  1. May 14, 2018 at 6:36 AM
    #1
    RobinElectronics

    RobinElectronics [OP] New Member

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    Hey everyone,

    I am noticing that on the 2018 Tundra, there is no constant 12 volt power in the 7 pin trailer wiring. I am talking about the factory installed wiring package. Can anyone guide me on how to get an idea on how to get constant 12 volt power from the 7 pin trailer wiring when the truck is off?

    Thanks,

    David
     
  2. May 14, 2018 at 9:43 AM
    #2
    jeremyd

    jeremyd 2014 Crewmax SR5

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    I have a 2014 that has 12 volts on pin 7 when the ignition is on. Did you try it with the ignition on?

    The reason I ask is because I don't think it's wired the other way.
     
  3. May 14, 2018 at 10:31 AM
    #3
    Wintyfresh

    Wintyfresh New Member

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    I think you'd need to run a new (fused) wire from the battery.
     
    NewImprovedRon likes this.
  4. May 14, 2018 at 4:11 PM
    #4
    TTund16

    TTund16 New Member

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    I think pin #4?? is auxiliary 12v ... but the ignition must be on from what I have read here. I haven't tested it myself.
     
  5. Oct 25, 2020 at 12:55 PM
    #5
    Don308

    Don308 New Member

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    I too have been wanting this. A friend of mine has a Dodge 3/4 ton and his is wired hot all the time yet others are not. I’m told the reason is for safety. If you leave your rv trailer attached it can and will drain your truck battery and can leave you stranded. It would be nice if you could add a jumper in the fuse block to make it hot all the time.
     
  6. Oct 25, 2020 at 1:35 PM
    #6
    biebs96

    biebs96 my other truck is a big brown truck

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    Following.

    Id like to know as well.
     
  7. Oct 25, 2020 at 1:54 PM
    #7
    jrquist

    jrquist Canon Shooter

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    Here is what is on every pin. You would need to run a separate wire to have a constant hot.


    7 pin rv trailer plug.jpg
     
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  8. Oct 25, 2020 at 5:47 PM
    #8
    TTund16

    TTund16 New Member

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    Wonder how many amps you can draw from pin 4.
     
  9. Oct 26, 2020 at 11:08 AM
    #9
    Levinger79

    Levinger79 New Member

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    There is no constant hot on that 7 pin plug. I had to run a new fused wire back from the battery to power my bed lights.
     
  10. Oct 26, 2020 at 11:23 AM
    #10
    ElNopal

    ElNopal Stay classy and be well

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    ^^^ This^^^^
     
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  11. Oct 26, 2020 at 4:58 PM
    #11
    Redpill

    Redpill New Member

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    Mine has constant 12v, it charges my dump trailer battery as I run down the road. I believe it comes from pin #4.
     
  12. Oct 26, 2020 at 5:02 PM
    #12
    Jim LE 1301

    Jim LE 1301 Camaro Lover, SSEM # 11,TTC#179

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    I believe that it only has power when the engine is running not while off.
     
  13. Oct 26, 2020 at 5:21 PM
    #13
    Redpill

    Redpill New Member

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    Yes sir, I should have said it has constant 12v while key is in the on position.
     
  14. Oct 26, 2020 at 5:24 PM
    #14
    Ruggybuggy

    Ruggybuggy Seasoned Veteran

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    Are you not worried about running your battery dead? :notsure:
     
  15. Apr 13, 2022 at 2:35 PM
    #15
    Conflicted

    Conflicted New Member

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    I keep it really clean!
    I am looking to install bed lights also. What size fuse did you use for your line?
     
    TTund16 likes this.
  16. Apr 13, 2022 at 2:49 PM
    #16
    TTund16

    TTund16 New Member

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    You guys know how many amps can pin #4 supply? and pin #7 if you know.
     
  17. Apr 13, 2022 at 8:35 PM
    #17
    Jim LE 1301

    Jim LE 1301 Camaro Lover, SSEM # 11,TTC#179

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    :notsure:
     

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