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brute48's avatar
brute48
Explorer
Jul 02, 2018

Help!! Intermittent 12 Volt issue

I am having a intermittent 12 V issue that I need help figuring out. Went camping this past weekend and discovered no power at all once I disconnected from my truck. Everything was off. Like I had turned the battery switch to off. Turned on my inverter and everything worked again. Turned inverter off everything dead again. Hooked the 7 pin connector back up to the truck and alll of my 12 v stuff worked ....pulled plug and dead ... well you get the picture. So we had power all weekend via solar and inverter or my generator. Came home today and disconnected and now my 12 v system is working the way it should. What could be causing this issue? I have looked at the basic stuff like fuses, breakers and for loose wires that I can see. All looks good. Is there a relay or switch that could be getting stuck when I plug into my truck? Any help will be appreciated.
  • brute48's avatar
    brute48
    Explorer
    Jul 03, 2018
    Ok. Finally discovered what the issue is. I moved and wiggled the wire around the 40 amp breakers and the lights would flash off and on. I will be picking up some new breakers tomorrow and replacing the bad ones.
  • brute48's avatar
    brute48
    Explorer
    Jul 02, 2018
    Thank you all for your advice. I am going to check the two automotive style breakers and see if they might be the culprit. I will update if and when I figure this thing out.
  • mike-s's avatar
    mike-s
    Explorer
    Jul 02, 2018
    Sounds like the battery to inverter connection is fine (or the inverter wouldn't be working when disconnected from the TV), but the battery to panel connection isn't.

    When the inverter is on, it's apparently providing power to the panel and converter, so the converter is providing power to all the 12V stuff. It really shouldn't be set up that way, because it means when everything's working normally, the battery ends up trying to charge itself via the inverter/converter, which can be a huge power drain. One easy way to fix that is to put the converter on its own AC breaker, and turn that off when not connected to shore power.

    Re-check the battery connections at both the battery and the panel/converter. Both + and -. There may be a ground bar mounted behind the panel, which you may have to pull the panel out a bit to get to.
  • TakingThe5th's avatar
    TakingThe5th
    Explorer
    Jul 02, 2018
    MEXICOWANDERER wrote:
    Was the onboard battery down at the corner saloon during all this?

    Audit every single terminal and every single device between the onboard battery and the fuse panel.

    INSIDE THE INVERTER is an automatic changeover relay that provides power to the CONverter get it? The INverter is Dick-Smithing the battery and providing AC power to the CONverter. You are seeing power from the CONverter. This is exactly like what government does with your taxes.

    X2. Also you could have a broken battery post, an internal break in the battery. A long shot, but "Hanging" your battery by some short cables or "coaxing" a stubborn cable off the battery could cause that problem, amongst other reasons. Wiggle the posts.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Jul 02, 2018
    Was the onboard battery down at the corner saloon during all this?

    Audit every single terminal and every single device between the onboard battery and the fuse panel.

    INSIDE THE INVERTER is an automatic changeover relay that provides power to the CONverter get it? The INverter is Dick-Smithing the battery and providing AC power to the CONverter. You are seeing power from the CONverter. This is exactly like what government does with your taxes.
  • 3_tons's avatar
    3_tons
    Explorer III
    Jul 02, 2018
    Questions:

    Is your inverter wired to power up the camper’s onboard converter charger too?...IF so, that would be a path to supply the 12v side of things...

    Also, Battery cabling to inverter should be dedicated for inverter only and of heavier AWG gauge...Battery cabling to camper’s 12v fuse panel (via the cut off switch) is separate from inverter..
  • brute48's avatar
    brute48
    Explorer
    Jul 02, 2018
    My inverter is a 1500 pure sine wave inverter for AC power. Came with my weekender solar kit.
  • 3_tons's avatar
    3_tons
    Explorer III
    Jul 02, 2018
    Well IF I have this right it appears that the inverter wiring (as well as the truck) was providing a current path to the camper that the normal battery cabling to main breaker-fuse panel could not, possibly due to a defective battery cutoff switch...

    IF this is a possibility, then one might assume that:

    a) the inverter 120v output supplies the onboard converter-charger, thus powering up the 12v circuitry....A potential ‘round robin’ affair where the inverter simultaniously attempts to charge the batteries.

    b) the truck alternator has its own path to the 12v circuitry.

    You don’t mention whether this is a basic inverter or a pass-thru inverter charger...

    Just for WAG speculation only

    3 tons

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