Battery was hooked up wrong!

Discussion in 'General RVing' started by carlitguy, Aug 10, 2008.

  1. carlitguy

    carlitguy New Member

    I bought a used tent trailer for the kids to use.
    I noticed the battery had the white on the positive terminal but when I look at the back of the converter it says it is the normal negative post for the white wire.
    I checked the glass fuse inside the converter and it is still good.'
    When I am plugged in there is power to the wall plugs and when I check the fuses there is power to them. The problem is there is no power to either the ceiling lights or the furnace. This doesn't make sense as there is power to the fuses.
    Can it be anything else other than the converter? Did he 'poach it?
    Thanks, carlitguy
     
  2. C Nash

    C Nash Senior Member

    Re: Battery was hooked up wrong!

    If the battery is charged the 12v lights and furnace should work. look for a fuse after the pos battery post. Start at the battery and work forward with a VOM or 12v test light. Wow I must be loosing it thought I had just posted a answer to this Dean. Welcome to the forum Dean.
     
  3. ironart

    ironart New Member

    Re: Battery was hooked up wrong!

    I agree with Nash, 12 volt stuff should work.

    Well now were really into a delema. The automotive wiring "code" says that the black wire is the ground or negative wire and any other color, white, red, blue, yellow etc usually carries the positive side. Now in motor homes they use the national wiring code (like for houses) where the white is the neutral, green ground and black hot`......
    The problem comes in when you try to mix the two......The engine and auto side of the chassis uses the auto code....Black ground and red positive. The coach uses the other.
    The converter is using the National wiring code )as it should because it is producing 115 volts (like house current).....Follow the instruction on the converter and you should have no problems......There might be a diode in the converter power circuit to prevent any reverse connections....lets hope so.. that should protect the converter from "poaching" :(
     
  4. elkhartjim

    elkhartjim Senior Member

    Re: Battery was hooked up wrong!

    Dang...its good to have a lectrician on board. A big ole welcome from Texas pardner.
     
  5. ironart

    ironart New Member

    Re: Battery was hooked up wrong!

    Hi Jim,
    Yep was one at about 5 years old, helping my dad (who was an electrical contractor) screw on switch plates after he made the connections....
    Was a contractor myself at age 18 (1963)....Then went on to get general building and plumbing and HVAC and solar...Just a glutton for punishment.
    Now I am a starving metal artist.
     
  6. carlitguy

    carlitguy New Member

    Re: Battery was hooked up wrong!

    Ironart, I took the converter apart (yes I unplugged it first!) and there was a 4 amp glass fuse. It was still good.
    On the inside of the converter there was a diode soldered in at the factory between two white wires. Does this have to be replaced?
    I do have operating plugs, 15 amp fuses are showing power wth a test light but the furnace and ceiling lights are not operating. I do have propane as well as a fully charged battery.
    Thanks for the replies
    carlitguy.
     
  7. ironart

    ironart New Member

    Re: Battery was hooked up wrong!

    Hi Carlitguy,
    Lets start over. If I am reading your post correctly...The Tent trailer came with the converter. When you got the trailer, you noticed that the wires were connected wrong.
    Did you have 115V coming from the converter at that time..?? Did the lights and furnace ever work or have you just noticed that they don't.
    Tent trailers are pretty basic and you don't have a lot of crap to worry about....If worst comes to worst you can just run another hot line to the furnace. I would connect all of the existing wires together and heat the system from the furnace.(back end it). If there is a broken wire or bad connection, you will get the 12 volts to the ceiling lights from both directions.... You could remove the light and check the connection and also the connection at the furnace although there should be 2 fuses...one for the lights and another for the furnace...at least that is the way most coaches are wired.
    Is there a main fuse block that you can check..?? Possibly when who ever connected the converter miss-wired it and that could have blown a fuse...Hard to tell not being there.
    As for the Diode...They are designed into the circuits for just kind of mistake....It should have done it's job and be OK
    We are talking about 2 different problems here.....Try to remove the converter and run seperate wires from it to a 12V source...see if you get 115 V from it..??
    If you do then that problem is solved....If you don't...someone may have cooked it. The 12V problem is a whole other issue and has nothing to do with the converter.
     
  8. ironart

    ironart New Member

    Re: Battery was hooked up wrong!

    OK, I am worst that Nash......I am comfusing myself the Converter converts 115 volts to 12 volts DC It is like a battery charger but with fixed voltage and no regulator.It is like the power supply in your computer.
    an INVERTER (WHICH IS WHAT I THOUGHT YOU WERE TALKING ABOUT) :question: Changes 12V DC to 115V AC This is what most of us have in our coaches so we can watch TV without running the Gen set.
    Now Which one do you have..??? a Converter (115/VAC to 12VDC) or an Inverter (12VDC to 115VAC) :question: :question: :question: :question:
     
  9. Kirk

    Kirk Senior Member

    RE: Battery was hooked up wrong!



    I was not a licensed electrician, but I did spend 40 years as an electronic/mechanical service tech. and I have owned and repaired my RVs since 1972. Based on that I would offer a couple of comments.

    "The converter is using the National wiring code )as it should because it is producing 115 volts (like house current)."

    This is not the case. What your converter does is to take a 120V-AC power supply and convert that to a 12V-DC output. The actual voltage out, if properly adjusted will be about 13.5V so that it will also charge the battery as well as to supply 12V power for things like the lights and the furnace.

    You should have 120V supply into the converter and 12V out. The battery on most RVs does use white for the positive side and black fo negative. I would remove the lead from the battery negative terminal first and measure the resistance from that lead to the chassis ground. It should be 0 ohms or nearly that. Then measure from the positive to the negative and that will tell you the state of the battery. That voltage should fall between about 10.5V and 13.6V if the battery is anywere near a good one, All of this I would do with no shore power (120V-AC) connected or the power plug not connected.

    The next thing that I would do is to connect the leads to the battery and then connect the RV to shore power. Now measure to see what the voltage reads between the positive and negative posts of the battery. If the converter is working and if it is attempting to charge the RV's battery, that voltabe will be higher than what you read with no negative lead connected. If the battery is fully charged that voltage should be about 13.5V. Too high and it will boil the water out of the battery and too low and it won't charge the batterry. But you will not know the peak voltage until the battery is charged, or by removing the battery from the circuit and measuring across the two leads to the battery. You can also measure that at the output terminals of the converter, but the battery still has to be out of the circuit to get an accurate reading.



    With the typical, low pirce converters that most RVs came from the factory, the battery is needed in the circuit while in use as a filter for the poor quality output of the converter, but removing it for just a few minutes to measure should not harm anything.



    Be sure that you have the battery terminal conncetions clean and tight. You can use a water & baking soda mix to neutralize any acid in the corossion on the battery terminals. You should also check the liquid level in your battery cells and if it is not up to the slot in each cell, use distilled water to bring it up to the proper level. If this still doesn't help, any battery store can test the battery for you.
     
  10. carlitguy

    carlitguy New Member

    Re: Battery was hooked up wrong!

    Thank you for your replies. I will let you know how I make out. Iam embarassed because I have been in the RV industry for 9 years and this is beating me. Mind you, I am in Sales.
    carlitguy
     
  11. C Nash

    C Nash Senior Member

    Re: Battery was hooked up wrong!

    Nothing to be embarassed about carlitguy. Still think you should have a wire from the battery that supplies the 12 volts to the lights and furnace. have you looked for a wire around the battery that maybe is disconnected? Are there any other wires other than the white and both battery cables on the battery?
     
  12. carlitguy

    carlitguy New Member

    Re: Battery was hooked up wrong!

    My problem is I do have power to the converter but this is where it ends. It doesn't go out to the lights or furnace. This is what has me baffled.
    carlitguy
     
  13. C Nash

    C Nash Senior Member

    Re: Battery was hooked up wrong!

    Are you checking on the white wire that comes from the battery to the converter? If so this is the wire that keeps the batt charged if I am thinking right. There should be another wire from the battery that supplies the 12 v to the inside.
     
  14. carlitguy

    carlitguy New Member

    Re: Battery was hooked up wrong!

    Tada!
    I gave up and befotre I bought a converter I had a tech from work come over.
    On a tent trailer the stove and sink flip over so you can close the unit. There is a microswitch that is depressed and activates the electrics which in turn will let propane flow. It is so that propane and the electrics are disabled when the unit is closed.
    The switch was perfectly fine but when the unit was closed the weoght was not enough to close the switch. I guess if you had pots, dishes, can goods, etc it would be.
    I solved it by putting a small piece of wood so it fully depresses.
    Dean in Canada
     
  15. C Nash

    C Nash Senior Member

    Re: Battery was hooked up wrong!

    Thanks for the update Dean. Glad you found the problem.
     

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