Have A Charge Line Question For Running Fridge On DC

Discussion in 'Refrigerators and Coolers' started by TX_F2, May 27, 2010.

  1. TX_F2

    TX_F2 New Member

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    Ok, I now have a charge line on my TV so that I can run the fridge on DC while on the road, but I have a question.

    There is an in line fuse going from the pup battery into the pup. I know that I have to have the fuse in there if I want to boondock and run off the pup battery.

    But do I need to have that fuse in there also to have the TV charge line run the fridge on DC while we are traveling or will it work without the fuse in it ?

    TIA
     
  2. rabird

    rabird Howdy!

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    You charge line should have a fuse in the fuse box of the vehicle or in line near the vehicle battery.
    Fuses protect the wires if a short occurs.
     
  3. TX_F2

    TX_F2 New Member

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    I am a little dense with this, so please bear with me. [:!] lol


    I understand that I have to have a fuse in the TV fuse box for the charge line to work. I do have all my fuses in the TV fuse box and the charge line is working as far as I can tell. With the TV turned off I took a mutimeter to the TV 7 pin plug and put the red lead on the # 4 pin and the black lead on the # 1 pin and the multimeter showed 12.4x volts.

    This is the in line fuse (30 amp) just outside the battery that I am talking about:

    [​IMG]


    With the pup in the closed position, NO fuse in that in line fuse holder and the 7 pin plug NOT connected to the TV, this is what I did:

    Turned on outside pup light - did not come on

    Then I put the fuse in the in line fuse holder and turned outside pup light on again - light came on


    Next I took the fuse out of the in line fuse holder again, then connected the 7 pin plug. Turned on the outside pup light and it came ON.

    Because of this, I am assuming that the TV charge line is working, and that the outside pup light came on getting power directly from the TV and that the pup battery is totally bypassed since the fuse was out ?

    I guess this is where I am getting confused. The fuse MUST be in to use the pup battery to turn on the outside pup light, if you take that fuse out then the light will not come on. But with the fuse out and the 7 pin plug connected, the light will come on.

    I thought the "flow" was like this:

    TV charge line - pup battery - pup (lights, outlets, ect.)

    So how / why does the pup's outside light come on when the 7 pin plug is connected to the TV but that in line fuse near the battery is removed ?

    Am I making sense ? [?:~{]
     
  4. rabird

    rabird Howdy!

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    The battery is t'd into the same line that comes from the vehicle, either can feed the PU.
    With the fuse in, the PU will have power and the vehicle will give the battery a small charge while towing.
    Since your charge line is always 'hot' (not off when the ignition is off), a dead PU battery can discharge the vehicle battery if the vehicle is not running. Also, a fridge operating on 12v can drain the vehicle AND PU battery while stopped for lunch.

    When not camping, pull the fuse at the PU battery so the propane/co detector don't drain the PU battery! Charge the PU battery overnight monthly & before and after each trip.
     
  5. TX_F2

    TX_F2 New Member

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    That part bolded is what has me confused because with the fuse OUT and the 7 pin plug connected to the TV, my pup's outside light will turn on, so the pup is still getting power from the TV without the fuse in. [?:~{]

    Now if you don't have the 7 pin plug connected to the TV and the fuse is OUT, the outside light will not turn on unless you put the fuse in.

    This is why I am wondering if I needed that fuse in to power the fridge on DC when towing, because the pup seems to have power from the TV even when the fuse is out, otherwise why would the outside light be able to be turned on ?


    Thanks for dealing with me on this rabird...............hope I am not making you pull your hair out trying to explain it to me. [:!]
     
  6. rabird

    rabird Howdy!

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    The fridge ought to be direct wired to the charge line from the vehicle (also to the PU battery via the tee if fuse is in).
    Some folks disconnect their PU battery (via the fuse or battery disconnect) to prevent the fridge from drain the PU battery.

    Basically you have two power sources, use one or the other or both.


    I need to add that the breakaway switch needs battery power and may require the fuse to be in unless the breakaway switch is sired directly to the battery. Breakaway is for trailer brakes if the trailer comes loose from the vehicle while towing.
     
  7. JTHale13

    JTHale13 "That's gonna leave a mark!"

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    No you don't need that fuse in to run the fridge off you tv while driving down the road but to my knowledge there is no reason not to have it in because by having that fuse in your tv will charge you pu battery and then when you get to camp your pu should have a full battery if you for some reason need to use it. when you have your camper plugged into electric and you have the fuse in that will also charge your battery because your pu's power converter should have a line for that. You can confirm that by plugging in your pu either at home or a campsite and un hooking the battery and then connecting a multi meter to the battery cables and you should see a low voltage reading which is like using a trickle charger.
     
  8. TX_F2

    TX_F2 New Member

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    Oh, man, I totally forgot about the breakaway switch. The fuse does have to be in for the breakaway switch. Thanks rabird.





    Thank you for the reply JT [8D]

    I will put the fuse in when towing/camping and then take it out when the pup is being stored in the garage between trips.
     

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