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How to make 12 volt charger stay on all the time.

Discussion in '3rd Gen Tundras (2014+)' started by jaredmillerdvm, Apr 14, 2018.

  1. Apr 14, 2018 at 7:21 PM
    #1
    jaredmillerdvm

    jaredmillerdvm [OP] Mods will never end!!

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    Anyone figure out how to make the 12 volt charger stay on even when truck is off?
     
  2. Apr 14, 2018 at 7:40 PM
    #2
    nk1794

    nk1794 Always torque to spec

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    Can you explain what you mean? Sorry I'm a little slow. :D
     
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  3. Apr 14, 2018 at 7:48 PM
    #3
    Prostar 190

    Prostar 190 WHITE is the SLOWEST color!!!

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    I'm sure you could just change the power wire to a constant hot by doing a search with a test light.
     
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  4. Apr 14, 2018 at 7:54 PM
    #4
    NewImprovedRon

    NewImprovedRon SouthBoundSteve Fan Club President

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    Are you talking about charging something like a cell phone when the truck is off? I would think that changing the power to a continuous source versus an ignition circuit would work.
     
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  5. Apr 14, 2018 at 7:57 PM
    #5
    nk1794

    nk1794 Always torque to spec

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  6. Apr 15, 2018 at 1:34 AM
    #6
    jaredmillerdvm

    jaredmillerdvm [OP] Mods will never end!!

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    @nk1794 my 07 Chevy had one that stayed on all the time and the battery never went dead. I would imagine that it would only drain the battery if you left something plugged in for days at a time without starting the truck. Or maybe they had something like you posted installed from factory. Who knows but it would be nice to have one stay on without having the truck running.
     
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  7. Apr 15, 2018 at 8:22 AM
    #7
    nk1794

    nk1794 Always torque to spec

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    OK. I thought you were doing constant charging.....It's easy to do. Get one of these and tap into one of the fuses at the driver's foot well. Obviously you want to look for a fuse that's always on and run the wire to your outlet and swap it out. You will have to do a little cutting and crimping at that end.

    upload_2018-4-15_8-15-39.jpg

    You can use this tester to find and test the fuse that's always on.
    upload_2018-4-15_8-19-53.jpg
     
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  8. Apr 15, 2018 at 9:22 AM
    #8
    Sting Ray

    Sting Ray New Member

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    Not enough space here...

    My wife's Jeep has a constant on plug and her battery doesn't die. I don't think it would be an issue unless you were constantly using it... Also, pretty cool thing about it is you just move the fuse one oring over to either have it constant on or with ignition.
     
  9. Apr 15, 2018 at 10:18 AM
    #9
    eddiesteele

    eddiesteele New Member

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  10. Apr 15, 2018 at 11:51 AM
    #10
    rocky_mtn_trd

    rocky_mtn_trd Voided Warranty

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    I currently have @TundraTex looking into this, but he has a very busy schedule. I'm sure he'll get back to me very soon on it and I'll post up a DIY for everyone.
     
  11. Apr 15, 2018 at 1:01 PM
    #11
    rocky_mtn_trd

    rocky_mtn_trd Voided Warranty

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    I have a feeling this is going to be an add-a-fuse moment. The relay seems to be stashed in the main body ECU (which i'm not even sure where that's located) and is inaccessible. I've read there is a RED wire coming from the main body ECU that powers all the 12v outlets that can be de-pinned and ran to a constant 12v fused power supply. It may be easier to just find an always hot fused 12v source and tap into it so long as you don't overload that circuit. Then run 12v constant to the outlets. Sure would be nice to find out about the de-pinning of the power outlet wire at the ECU as this would catch ALL the outlets at once.
     
  12. Apr 16, 2018 at 3:07 AM
    #12
    TundraTex

    TundraTex Get your FRAC on!

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    EDITED: When I originally wrote this post I had only briefly looked at the wiring diagrams. After taking more time to investigate and actually crawl under the dash, there is a pretty easy way to do this. Check out Post 33 for a picture of the driver's side kick panel fuse block and an unused 12 Volt Fuse slot.

    Hope this provides some food for thought. It's now number 37 on my list of things I'll do when I have the time.
     
    Last edited: Apr 20, 2018
  13. Apr 16, 2018 at 2:16 PM
    #13
    jaredmillerdvm

    jaredmillerdvm [OP] Mods will never end!!

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    @TundraTex have you seen this? Think it would work for the tundras? I just looked under the hood and couldn’t find a relay for the 12volt chargers? Do you know which relay it would be?
     
  14. Apr 16, 2018 at 2:19 PM
    #14
    rocky_mtn_trd

    rocky_mtn_trd Voided Warranty

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    It's because the relay is integrated in the main body ECU. It is not able to be jumpered and/or soldered like in the Tacos and 4 Runners.
     
  15. Apr 16, 2018 at 2:26 PM
    #15
    n2deep

    n2deep Overlander - Speed Glamper

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    Just run a dedicated wire to the battery -fused of course. Can also run a heavier gauge if needed.
     
  16. Apr 16, 2018 at 2:49 PM
    #16
    Skippy

    Skippy New Member

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    @nk1794, I see another mod with video in your future

    fortuneteller.jpg
     
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  17. Apr 16, 2018 at 3:12 PM
    #17
    nk1794

    nk1794 Always torque to spec

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    You are good! :rofl:
     
    Last edited: Apr 16, 2018
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  18. Apr 16, 2018 at 3:23 PM
    #18
    Skippy

    Skippy New Member

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    ^^^^ Don't know how I missed that, and staying tuned.
     
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  19. Apr 16, 2018 at 6:53 PM
    #19
    MarkM0369

    MarkM0369 New Member

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    I did one of my 12v lighter plugs when changing out the stereo, there is a yellow wire in the radio harness that is always hot, simple enough to drop it down to power a plug and just cap the wire that is on with the key. 2017 SR5
     
  20. Apr 16, 2018 at 8:44 PM
    #20
    eddiesteele

    eddiesteele New Member

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    for my blackvue dashcam im using THIS to run the dashcam while the truck is off to keep the battery from draining to far down. Im sure adding a second one with a dedicated outlet or even running it strait to the outlets in the center console would work.
     
  21. Apr 16, 2018 at 11:30 PM
    #21
    bj46-taco-tundra

    bj46-taco-tundra New Member

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    Add a fuse to the horn off the fuse panel was how I was able to power a charging USB plug to always stay active.
     
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  22. Apr 17, 2018 at 1:56 PM
    #22
    Brimaster

    Brimaster New Member

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    this is one thing I missed when i moved from the xterra to the tundra. All the lighter plugs were active all the time so it was nice when tailgating to be able to connect stuff without having to run the vehicle. I'll keep a watch on this thread so when the time comes I can do this mod.
     
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  23. Apr 17, 2018 at 2:32 PM
    #23
    nk1794

    nk1794 Always torque to spec

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    Someone should do a DIY video on this. :D
     
  24. Apr 17, 2018 at 2:44 PM
    #24
    Over the LINE

    Over the LINE New Member

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    I pulled a home run from my under hood fuse block while I was running wires for my light switches. Fuse block through firewall, then "over the river and through the woods" to the drivers side 12 volt. I only did one because I like having one always hot and one switched. I then re-used the abandoned switched wire for my dash camera. Remember to fuse the circuit to match it's original max amps.

    Disclaimer: I am not now nor have I ever been a licensed electrician, automotive or other, but I do play one in barrooms.

    P6280003.jpg
    P6280007.jpg
    P6280002.jpg
     
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  25. Apr 17, 2018 at 2:45 PM
    #25
    nk1794

    nk1794 Always torque to spec

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    Nice job!
     
  26. Apr 17, 2018 at 2:55 PM
    #26
    Skippy

    Skippy New Member

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    You read my mind :thumbsup:
    That way folks like me have detailed step by step
     
  27. Apr 17, 2018 at 3:01 PM
    #27
    nk1794

    nk1794 Always torque to spec

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    I'll do one for you, Skippy. :D
     
  28. Apr 17, 2018 at 3:14 PM
    #28
    Skippy

    Skippy New Member

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    Tap the yellow wire in the radio, and that way if I EVER get around to my front camera install I can kill 2 birds with one stone :hattip:

    images.jpg
     
  29. Apr 17, 2018 at 3:15 PM
    #29
    nk1794

    nk1794 Always torque to spec

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    Looks like it’s going to be a really short video.
     
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  30. Apr 20, 2018 at 6:01 AM
    #30
    jaredmillerdvm

    jaredmillerdvm [OP] Mods will never end!!

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    Anybody working on a video or step by step?
     

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