No power from Battery

Battery cut off switch somewhere?

Anyway, welcome to the Forum...members with much more knowledgeable than me will certainly solve this one for you....

No battery cutoff switch anywhere. If there is I cannot find it.

Follow the red wire from the battery, it usually connects under the trailer to a circuit breaker. There should be a button to reset it.

I saw that on you-tube and on here also. I am not saying there is not a reset button but I could not find it. I have two sets of a two prong device with wires going to them. Was told that a tiny reset button was on one going to the trailer. I did not dis-connect the wires - Is that necessary to set the reset button???

Navy E-8 wrote:
I saw that on you-tube and on here also. I am not saying there is not a reset button but I could not find it. I have two sets of a two prong device with wires going to them. Was told that a tiny reset button was on one going to the trailer. I did not dis-connect the wires - Is that necessary to set the reset button???

No, it's not necessary but, if there is a fault, it will immediately open the circuit breaker. Worth a try at resetting.

These little "tin can" circuit breakers are cheap, can be found at auto parts stores, and are easy to replace, should that be necessary. They will be marked with the value for amperage.

Navy, in your original post, are you saying that you get 12vdc in the trailer if it is plugged in? Your 12v stuff works? Then when you disconnect 120, the 12vdc goes away?

Before anything else, get a multimeter. Even a $5 or free with purchase Harbor Freight one. Otherwise, you're flying blind. You need o be able to measure things.

Navy, in your original post, are you saying that you get 12vdc in the trailer if it is plugged in? Your 12v stuff works? Then when you disconnect 120, the 12vdc goes away?


Yes. That is correct. Everything works fine while I have shore power hooked up or if I am connected to the truck and it has to be running otherwise the 12v stuff does not work. There are no blown fuses that I can find and there are no battery cutoff switches and there are no reset switches that I can find between the battery and trailer.....

Unplug trailer from AC Power Source and Truck umbilical cord

Measure DC Voltage on BOTH sides of the 'DC Circuit Breaker' (tin can with dual studs)

DC on battery side but not on trailer side....replace the DC Circuit Breaker

My 30A resettable breaker located on the trailer frame failed and didn't reset. Same symptoms as yours.

If you are intimidated by a multimeter, a 12V circuit tester such as THIS will find your problem. You can buy them at any auto parts store and most big box stores. But I do highly recommend any camper owner to invest in a multimeter.

With the camper unplugged, if the tester lights on one side of the circuit breaker but not the other side, the breaker has failed. If it lights on both sides, the problem is downstream away from the battery. If neither side lights, the problem is towards the battery.
Make sure you are using a known good ground if the tester can't reach the battery negative post.