Electrical issues

Discussion in 'Power - Site Power/Batteries/Generators/Solar' started by MileHigh, Jun 20, 2013.

  1. MileHigh

    MileHigh Active Member

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    An issue that I would like help with. Had electrical and all worked well. Went to the next spot without hookups and the battery was dead. Reverse polarity fuse in the converter box was blown but no chance that happened. Plugging in to power at the next site and battery won't charge and still no interior or exterior lights. I am thinking the converter is bad. Any thoughts?
     
  2. Snow

    Snow Well-Known Member

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    did you replace the fuse and verify that the battery is connected correctly ??
     
  3. MileHigh

    MileHigh Active Member

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    Yes. Fuse was replaced and battery is 100% right.
    8
     
  4. Raycfe

    Raycfe Waterford Ct.

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    or the positive battery lead is shorted out somewhere. If fuse blows ....... look more toward a battery/wiring problem. Disconnect the cables, and replace the fuse, charge the battery would be the first things I would do.
     
  5. MileHigh

    MileHigh Active Member

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    The battery is not charging when plugged into 115volts. It's also not charging when connected to the TV. Camper is 2003 Rockwood and TV is 2008 4Runner with 7 pin trailer plug.
     
  6. Raycfe

    Raycfe Waterford Ct.

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    You will have to check the charging voltage with a voltmeter. First at the 4runners plug, then at battery, with the 4runner running. With the PUP not plugged into 115 VAC. Should have over 13 volts.
     
  7. MileHigh

    MileHigh Active Member

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    Back home now so I can give more details as I'm not using my phone. We were dry camping and all seemed well. 12v LED lights were working fine. At the next campsite, nothing. Battery was dead and the reverse polarity fuse in the WFCO 3712 was blown. I've replaced the one blown fuse and checked all the other with an ohm meter. Nothing was changed in the wiring so I'm assuming that there may have been a short in the system somewhere. I checked the voltages at the back of the converter and they are in the 2.0 volt range with the battery connected and 0 volts without the battery. Voltages were checked at both the negative bus bar and the fuses/individual circuits. Kind of confused as the positive battery cable is grounded to the trailer chassis - shouldn't the negative one be grounded or am I just using my automotive DC circuit knowledge? I've traced the wiring along the frame of the chassis and didn't see any signs of a short. Could the converter go bad and drain the battery? The battery voltage after disconnected from the RV is 8.7 volts - way too low and probably gone but I'll charge it to see what happens first. Should the interior/exterior lights work without the battery just being ran on the converter?
     
  8. rabird

    rabird Howdy!

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    Positive ground [?:~{] [?:~{]

    low voltage can be dirty/poor connections
     
  9. COdreaming

    COdreaming New Member

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    Huh. My trailer's negative cable goes to trailer frame ground.
     
  10. MileHigh

    MileHigh Active Member

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    The cable thing has me confused for sure but it is the way the trailer has been since I got it last year and things have been fine up until last week...
     
  11. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    Just mentioning: on a PUP the negative wire is white and the positive wire is black.
     
  12. SUPERKSR

    SUPERKSR Member

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    That was my first thought...
     
  13. MileHigh

    MileHigh Active Member

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    Since I bought the camper, the white cable was connected to the positive side of the battery cable. No issues in the past year using either shore power or the battery alone. I'm going to do more troubleshooting tomorrow and may connect the battery the opposite way that it has been for the past year to see what happens. In any case, my guess is that the converter is bad.
     
  14. rabird

    rabird Howdy!

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    My volt meter will read volts (red to + and black to -) and neg volts when hooked up incorrectly.

    I'd use this feature to test the output of the converter, red meter wire to black batt wire, black meter wire to white batt wire should give volts and not neg volts.

    Try this on the batt, red meter wire to batt + post ...
     
  15. dion

    dion Member

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    Definitely, negative should be ground, positive "hot". As has been pointed out, in many trailers, white is negative ground, and black is positive hot. That color code is not a universal convention, but it's a popular one.

    When charging from the tow vehicle, the frames connect through the metal of the hitch. That's not a great electrical connection, so there should be a proper electrical connection made with wires on the wiring harness as well. But the connection through the hitch is at least solid enough to really mess things up if you tried to use a negative-ground car to charge a positive-ground trailer. Also, nobody makes a positive ground converter AFAIK.

    If indeed you've verified that the positive post of the battery is connected to the frame, then that would certainly explain why the reverse polarity fuse is blown.
     
  16. MileHigh

    MileHigh Active Member

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    I removed the WFCO 3712 converter and hooked it up to AC power in my shop. All outputs are at 0 volts. I will check several of the individual components but will probably just get a new converter. My guess is that it may have been bad when I bought the camper but the 12volt lights were still able to run with the battery hooked up backwards. Thankfully, we had several LED lights to hang from the ceiling and had 115VAC to charge cell phones. I'll give an update after the converter is replaced.
     
  17. MileHigh

    MileHigh Active Member

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    I just installed a new WFCO 8725 converter. For a couple of extra dollars, I upgraded from the 8712 and thought it would be worth it to get the extra power. Installation was pretty simple as I was able to reuse the old circuit breakers and had labeled everything. It is a little tight getting the AC lines back in but it's worth it now as everything works as it should. I never was able to get the 12v lights to come on without the battery being connected so I'm sure the converter was bad when I bought it and the previous owner had the battery in backwards. Hopefully, the battery comes back to life as well. Shows 13.64 volts while charging. I am going to properly label the battery connections so something like this doesn't happen again.
     
  18. N1BRU

    N1BRU New Member

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    Milehigh, Well, Glad everything worked out. With the battery hooked up backwards, everything worked untill the battery went dead and the converter burned up because of the reverse fuse blow. Most campers now days have white wire is ground and the black wire is positive(hot) I just bought a new 2013 Rockwood Freedom Pup and added a few electrical 12 volt plugs for breathing machines. I used the accessory wire, color grey for these outlets, also make sure you fuse any additional 12 volt lines you run just to be safe. Good luck with the new electrical set up.
     

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