Any solution for an "always on" 12 volt DC power point?

Discussion in 'The Garage' started by mb, Nov 18, 2012.

  1. mb

    mb Lifer

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    Short story: the 12 volt power outlets in my car are always on. I'd like them to only be active when the ignition is on or the car is in accessory mode.
    Anything I can easily do? I don't have any electronics experience to make something but I'm up for tearing apart the dash or console to do this.


    Longer story: all three of the 12v outlets in my 2013 Ford Fusion are always on, so I can't/don't want to leave anything plugged in when I'm not using the car.
    The car does have satellite radio built in but I have a lifetime sirius XM subscription that is tied to a portable unit. In my Accord I could just leave the portable unit plugged in all the time and it would only come on when the car was running. With the Fusion I will have to plug and unplug the thing. Same with my cell phone charger. I've never had a car that does this before.. I might get used to it but so far it is incredibly annoying.

    Is there something out there I could buy and install to do this? I tried looking on google but couldn't really find anything.
    If there's not something I could buy, is this even possible? Is it something a skilled mechanic or maybe even a car audio installer would know how to do?

    Thanks!
     
  2. EagleKeeper

    EagleKeeper Discussion Club Moderator<br>Elite Member
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    Any car installer should be able to help you.

    If you intend on using one of the existing outlets it will have to be traced back to the fuse box.
    Remove the wire to the fuse box and connect it to a non hot wire point that is live only by the accessory switch;

    It will require some detective skills with a meter (easier) that way.

    Or pay the $25-50 to an installer along with a box of donuts.
     
  3. NutBucket

    NutBucket Lifer

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    Probably would want to use a relay as to not overload the switched 12V source ;)
     
  4. mb

    mb Lifer

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    Awesome, I'll make some calls when I get back from vacation. Thanks!
     
  5. Plugers

    Plugers Senior member

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    X2 just cut the 12v lead to the socket(s), crimp connectors on the ends you just cut and run the trigger of the relay to an ignition on source.

    or just splice in a relay socket to the harness and plug the relay in.
     
    #5 Plugers, Nov 18, 2012
    Last edited: Nov 18, 2012
  6. DeviousTrap

    DeviousTrap Diamond Member

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    Edit> Whoops, didn't read the above post and suggested the same thing.

    Just wire in a relay behind the cig outlet, dont bother tracing the feed to the fuse box.
     
  7. phucheneh

    phucheneh Diamond Member

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    You'll be at the fusebox, anyhow.

    Put a fuse tap (real one, not a piece of wire jammed in with the fuse blade) in with a switched power source. Find something with a decent sized fuse (not a 5a control module fuse or something) to tap.

    Use that to power your relay coil. Then there's probably a chassis ground nearby that you can stick an extra ring terminal on.

    Then find the power feed (or common output) for the power outlets in the fusebox. Hopefully they're all on the same circuit. Cut it. Hot side goes into the input of your relay switch, other side goes into the 'on' output (pin 87; not 87a if you have a five pin relay).

    Then all outlets are still using the stock fuse but you've interrupted either before or after with your ignition-controlled relay. So functionally, it's like Ford actually designed it right.
     
  8. Raduque

    Raduque Lifer

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    Honestly, this is something I wish EVERY car manufacturer did. 12v power points that don't have power with the vehicle off are a pain in the ass.

    Have you tried switching your sub to the car's radio?
     
  9. heymrdj

    heymrdj Diamond Member

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    This. I have a 2012 Civic and the fact it turns them off when the car is off drives me insane. Normally i'm grabbing lunch and need my phone to get that bit of charge as a hotspot by the time I reach the location. When I drive my 04 Expedition it's not an issue. But the Civic makes me want to pull my hair out on some days. I was told it was because these imports have such small batteries manufacturers are afraid of them constantly going dead. Civic is a 450CCA 41AH battery, my Expedition has a 850CCA Motocraft MAX battery, and even with the inverter running stuff in the truck it lasts forever and still cranks on the first bump.
     
  10. phucheneh

    phucheneh Diamond Member

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    'Proper' way, imo, is one switched and one not. The one in my dash next to the non-ashtray is switched. Center console is always on.

    If I was a manufacturer, though, I'd switch them all. Too damn many people with fourteen different stupid devices charging all the time.

    Help, I have two power outlets on the same circuit with three devices plugged into each. Why does the fuse keep blowing? :confused:
     
  11. heymrdj

    heymrdj Diamond Member

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    It's very difficult to get power points re-wired, especially on some models where the whole dash may literally have to come out. If someone doesn't want their car to drain, don't plug the darn thing in. We, as a society, should be attempting to raise the average IQ just a bit. If someone is killing their car or blowing fuses all the time, sounds like good revenue to the stealerships to me.
     
  12. phucheneh

    phucheneh Diamond Member

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    It's not the dealership, it's the manufacturer. They don't want to deal with warranty battery and/or fuse-related complaints.

    And it's really not that hard to rewire this stuff. The method I described above would only take me a few minutes to do.

    Going the other way is a little harder, since the switched power wire(s) that operates the outlet fuse(s) may feed something else (may not be able to just 'short' the supply to constant power). Worst case, get a $5 fuse holder and run an extra wire off the battery or the power input to the engine fusebox, and pass it through a grommet in the firewall.

    edit: when I saying 'wiring' and 'not hard,' do realize that I'm referring to someone with good wiring knowledge (and associated work habits). No condescension intended; people just need to know some basics before they start manipulating wiring. Many do not.
     
    #12 phucheneh, Nov 18, 2012
    Last edited: Nov 18, 2012
  13. sjwaste

    sjwaste Diamond Member

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    You need to use the switched 12V to drive a relay to the power socket. Right now it's wired into always on 12V. Don't wire the sockets directly to the switched 12V because that's often on a much lower capacity circuit, or even if its on a 20A, it may have significant draw from all of the onboard electronics.

    Are the 3 sockets on their own 20A fuses, or are all 3 on a single fuse? (check the factory wiring diagram). If that's the case, you can do a clean job by using a relay under the hood of the car coming off the battery, tap into a switched 12V source there, and run a single wire back into the cabin to the fuse box. Then you'll have switched sources.

    I'm sorry if I'm not explaining this well. I know you said you don't really know what you're doing, but I'm having trouble being more descriptive. If you have an audio shop in town, they will be able to do it for you. If you want to DIY, I can try and elaborate, but I don't have the same car as you so I won't be able to be too specific.
     
  14. sjwaste

    sjwaste Diamond Member

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    Heh, I actually prefer mine to all be wired into constant 12V. I don't leave stuff plugged in usually, at least nothing bigger than a cell phone, which isn't going to drain my battery for a long time. But what I do want is for my shit to work when I plug it in, even if I don't have the keys in it. So I've always modified mine the other way, to be always on.
     
  15. heymrdj

    heymrdj Diamond Member

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    This is what i mean. Jo Schmo cant just say this is bugging me and change it in half an hour. Anyone can unplug something from the socket.

    I also disagree about the fuse thing. Being on when the car is off vs on doesn't change what a user will plug in. Idiots are idiots, no matter what.
     
  16. phucheneh

    phucheneh Diamond Member

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    Joe Schmoe probably has the internet, though. He can read up on things like the basic theory of an electrical circuit, proper circuit protection, Ohm's law, ect. Hooray internet. :awe:

    And yeah, I realize that turning the outlets off won't save someone overloading the circuit when the car's on. I was just stating that the carmaker generally tries to do everything they can to avoid having complaints on new cars (for both promotional 'reliability' or 'quality' numbers and warranty costs).

    That's probably one reason you now get more power outlets with bigger fuses. Two outlets are often fused together for at least 30a...pretty absurd for the the ~18ga wire of one outlet to carry that.
     
  17. heymrdj

    heymrdj Diamond Member

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    Entertaining the idea that Jo Schmo would do all of that, what do you think the Warranty consequences are for Jo Schmo on a 2013 Fusion and messing with its JCB. Ford has always taken a fairly hardline warranty stance. I can only imagine if something actually happened to the computer or the JCB and them nitpicking some reason why the wiring caused it.
     
  18. natto fire

    natto fire Diamond Member

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    I just did this on my Jeep as well as adding a couple sockets and USB ports. I decided to use an independent toggle switch that I hid underneath the dash to switch the added receptacles.

    I am not going to make a blanket statement about how hard or easy this is to do, because it really varies on how professional you want it done/how the wiring is done in your car.

    I know many cars have an extra switched power in the fusebox, so tapping that can be an option, assuming it is capable of pulling the current. (if not, the relay method posted above would work for that) If doing the relay though, you might as well tap into the switched radio power. Basically there are a lot of options and difficulty varies with each solution as well as how "mechanic friendly" your car is.
     
  19. LTC8K6

    LTC8K6 Lifer

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    If you have the 115V outlet, it's not on all the time.
     
  20. JoeyP

    JoeyP Senior member

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    Look under the dash: you might already have an "accessory" power drop. My car has one with a ground, an always-on, and a switched-on. It even has a warning tag for max amp draw and a notice that the always-on can kill your battery.
     
  21. mb

    mb Lifer

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    Thanks for all the good info everyone - very helpful.
    I think, however, I found a product that will help. http://www.amazon.com/gp/product/B007NM7EUM/
    It appears that the USB ports are not always on. I feel kind of dumb for not thinking to look for something like this before, but I'm glad I found it before modifying the wiring in my car.

    I could, but the lifetime subscription is really a lifetime* subscription. You may only transfer your subscription either 4 or 5 times, and each transfer costs $75. Due to some POS radios failing over the years, I only have one transfer left. If I transfer it to my car or any other radio, that's it. That's the last device my subscription is good on and I would have to buy a new monthly/annual account after that. When that day comes I'll probably just use Pandora.
    I'm hoping to keep my portable unit going for as long as I can.
     
    #21 mb, Nov 19, 2012
    Last edited: Nov 19, 2012
  22. Thegonagle

    Thegonagle Diamond Member

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    If I was every manufacturer, I would make them stay on for a user-adjustable interval of 0 to 24 hours after the car is turned off (default 6-12 hours for people who don't read the owner's manual or otherwise learn their car's features).

    I would also banish the lawn tractor batteries that Honda uses in the Civic and the Fit.
     
  23. herm0016

    herm0016 Diamond Member

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    the chance of draining your battery is very low with an xm and a phone charger. I leave my xm, phone charger, and a compressor driven refrigerator plugged in all the time. The fridge draws about 1a when it is running. maybe 20% duty cycle.