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Switched v. unswitched car cigarette lighter?

  1. Jan 14, 2015 #1

    DaveC426913

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    Just bought a Dash Cam for my car - HP F310.

    It is supposed to power up when the car is turned on and power down when the car is turned off. Seems to me that the only way it can do this is if the cigarette lighter plug that it is plugged into is "switched" (i.e., the plug is powered only when the vehicle is on).

    The plug in my car is unswitched, i. e.it is powered even without keys in the ignition. So, yes. When I turn my car off, the device stays on. Were I to leave the F310 plugged in, it would drain my battery.

    Seems to me this is a critical design flaw, rendering the device essentially unusable (unless I want to yank it out every time I get out of the car).

    Can anyone suggest a solution? Is there a way I can get my cig lighter to turn off when the car is off? I would really rather not mess with my car's electrics.
     
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  3. Jan 14, 2015 #2

    phinds

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    Wow, I didn't know un-switched lighter sockets existed. That IS a problem. I can't see how you would get around that withOUT messing w/ the car's electronics. Good luck.

    Oh ... well, it is physically possible to ADD something to tap into the car's circuitry that would know when the ignition is off and could be used to drive a relay to the dash cam. By one way of looking at it, that would not be messing with the cars electronics ('cause not modifiying them, just taping onto one of the wires), but I think probably the way you are looking at it, it would be.
     
  4. Jan 14, 2015 #3

    DaveC426913

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    Well, you learn something new every day.

    Apparently, fuses have settings. Like 'ignition' and 'constant'.
     
  5. Jan 14, 2015 #4

    phinds

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    You've lost me there. How is that relevant to your problem?
     
  6. Jan 14, 2015 #5

    DaveC426913

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    The cigarette lighter plug in my 300M has a fuse. Apparently that particular fuse can be set so that it only comes on with the ignition.
     
  7. Jan 14, 2015 #6

    phinds

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    Ah. Nice.

    Jeez, this is thread is telling me lots of new stuff about cars.
     
  8. Jan 16, 2015 #7

    Mark44

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    How did you find this out? Settings on fuses is a new one on me.

    I would have found a hot lead that was switched and wired it in place of the unswitched hot wire that is currently connected to the lighter. I did essentially this on one of my motorcycles when I installed heated handgrips.
     
  9. Jan 16, 2015 #8

    DaveC426913

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    By asking on my 300M Enthusiasts' forum.
     
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