No 12v off battery's at panel

[Forum78]

Hi.

I just purchased a new Rockwood 8286WS fifthwheel.

The problem I'm having is im not getting the 12vdc volts from my battery to the panel. Plugged in I have 120 at the panel and 13.6 on the 12v circuit board and everything works.

I have 12.6vdc at the battery connection point to the panel but nothing at the panel.

Is there in inline fuse somewhere on the main line running from the battery to the inverter?

[hillsdaletc]

Depending on your system. You may have a circuit breaker near the battery. if it is grey plastic it should have a small black reset on the end of the small breaker. Or You may have inside the converter a 40 amp fuse that is orange. You will see two of them right together inside the door of your converter. One is from the converter charger and the other is for the line from the battery to the converter. Hope it is this simple for you.

[Forum78]

Thanks hillsdaletc

I am measuring voltage right at the terminal on the converter board when the wire comes from the battery. I did a visual on the fuses and looked good. I will have a good look in the front where the battery's are.

When I picked up the RV it was plugged in of course and everything worked fine. Brought home and plugged in and everything was good. Friday I did a test on all systems and unplugged the camper to check the battery's and all the lights went out. So I assummed dead batteries. Took them into a battery store and they checked out good. Less than a year old. I'm stumped.

[Happy Vibe]

So when you are disconnected from 120 you get 12V at the circuit board? But none of your lights work. Just making sure I understand.

[Forum78]

I have no 12v at the terminal at the bottom of the board when unplugged or when I trip the breaker for the inverter.

Barteries read 12.6v leaving the terminal block up front and reads nothing at the panel with no 110vac power. It reads the inverter voltage at both fused terminals when plugged in

Nothing works unless in plugged in. 120v of course or 12vdc

[Forum78]

Can anyone tell me where exactly the resettable terminal block is between the battery and converter?

[fonzie]

Have a look underneath trailer near tongue for mini-breaker and press black button to reset.....

[DaveSchwartz]

Sounds like your reverse-polarity fuses (those 40 amp orange ones) have been blown. The converter side of each one is tied to ground through a diode and a reverse polarity battery hookup will blow one or both to protect the converter.

When hooking up the battery in an RV, white is ground/battery negative and black is battery positive. That's not the automotive standard (black=negative, red=positive) but is in line with the A/C standard (white=neutral, black=hot) and is used because this is a mixed voltage system. The NEC talks about this. Better for a tech to treat all blacks as hot.

The converter is supplying 12VDC when its plugged in (and you would measure 12VDC on either side of the fuse) but when not plugged in to A/C you would only measure 12VDC on the battery side of the fuse because its not getting through to the distribution panel side.

[Forum78]

Thanks everyone. Just thought i would say im a jman electrician so this is really killing me i cant figure this out

So resettable fused terminals are in beside the batteries in the from compartment under the fifthwheel. They are mounted upside down couldn't see the black reset button but they where all good anyways not tripped/sticking out.

Checked both 40amp fuses with my meter. Both good.

So from the red wire on the load side of the grey breaker with the button i read 13.1vdc. Had the charger on the batteries previous just to make sure. When i go to the other end of the red wire on the terminal block in the fuse panel i read 0vdc.

So i unhooked the red wire and ran a new wire from the load side of the terminal to the panel, flipped the inverter breaker off first of course and boom 13.0vdc at the panel.

So my conclusion is i either have a broken wire between my batteries and panel or here is another fuse i don't know about. The worse part is about three feet from the grey resettable fuse the wire takes off into the trailer. How do i trace that without removing the whole underbelly.

[Tireguy397]

My brand new FR toy hauler was delivered to me with exact same problem. Diagnosis found bad circuit breaker beside my battery. Breaker has a wire that goes directly to positive terminal on battery. Breaker was low on the frame and had a plastic cover over it. The dam thing had continuity so at first I did not think it was bad. This breaker did not have a reset button. I finally took a small screwdriver and connected the two terminals on the breaker and boom, my lights and everything else that was 12v came on. Replaced breaker and no more problems.