Battery disconnect

Glad to hear you got it worked out.

Thanks for the help, got it done this morning

Lynnmor wrote:
I connect the breakaway switch after the disconnect switch so I can quickly turn off the brakes if the pin is pulled, the breakaway switch breaks or if a short develops in the wiring.

If any of that happens, I will be doing 70mph on the highway, so I don't plan to turn it off. If I really NEED to disconnect the breakaway switch in a hurry, I can cut one of its wires. I disagree strongly with having the breakaway switch after the battery disconnect.

I connect the breakaway switch after the disconnect switch so I can quickly turn off the brakes if the pin is pulled, the breakaway switch breaks or if a short develops in the wiring.

Bobbo wrote:
The only reason not to use the negative wire is the breakaway switch should never be disconnected from the battery, and disconnecting the negative does that. Either disconnect the positive, or be sure the battery disconnect switch is wired to the battery before the disconnect switch.

In answer to your question, you must not be disconnecting every hot wire or every ground wire going to the battery.

True, on a trailer it is imperative that the battery switch is in the positive line and the breakaway connected prior to the switch so it is always hot.

The only reason not to use the negative wire is the breakaway switch should never be disconnected from the battery, and disconnecting the negative does that. Either disconnect the positive, or be sure the battery disconnect switch is wired to the battery before the disconnect switch.

In answer to your question, you must not be disconnecting every hot wire or every ground wire going to the battery.

Most instructions for battery switches suggest the negative side. If it's a switch and there isn't any chance of the conductors shorting out against a ground anywhere, it really shouldn't matter. But the way most of the switches are made, there is a very thin piece of plastic between the electrical contacts and what it is mounted to and often with partially exposed contacts. If it's mounted in the negative side, shorting one of the contacts to the frame will have less potential for catastrophic damage. If the switch is on, shorting either side of it to the frame should have no effect, since the load side of the switch is already tied to the frame. Shorting the battery side to the frame could arc and is not completely without danger, but unless there are heavy loads it usually wouldn't cause a problem it would essentially be turning the switch on. If you put the switch on the positive side, and accidentally short it to the frame, there will be major sparks followed by much heat and, assuming the short is not quickly removed, likely fire.

Now why doesn't your switch turn off power? The only reasonable answer is that there is still a path from the battery around the switch. How many batteries do you have? How many load wires?

My trailer has an inverter tied directly to the battery as well as the load center inside the RV. I also have 2 batteries. So when my dealer installed the batteries, he hooked the negative side of the inverter to one of the batteries and the negative side of the load center in the RV to the other battery along with the cable between the batteries to run them in parallel. If I were to put a disconnect switch on either battery, there would still be a path connecting both batteries to the trailer's frame. This is because the load center is grounded to the frame and the inverter is grounded to the frame. To disconnect the batteries I would have to move both load wires to disconnect switch.

Look at all wires directly attaching to the batteries and make sure you understand what each one does. Then make sure all loads are on the appropriate side of the disconnect.

Photo?