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Good Sam Roadside Assistance

12 Volt Power Problems In My RV

by Joe
(hood river oregon)

I have 1980's Class C Midas Motorhome. Everything worked, a/c, micro, lights, fridge. I turned on the a/c and it popped a breaker. So I opened up the fuse panel inside the RV and it has normal household breakers and a row of fuses. It also has a red “test” button. I push the test button but it does not click, I reset all the breakers and checked all the fuses and still no lights.

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It works on battery, but I can’t seem to get all back working now. Last time this happened I unplugged the coach battery and plugged it back in and it worked somehow. That was off the microwave, now it’s the a/c. I am thinking I need a new circuit board or fuse box.

Thanks for the help.

ANSWER: Hi Joe I am going to assume that you have 120-volt power when you are plugged into electric and after you reset the breakers and that the only items still not working are your 12 volt DC lights and accessories.

If all of the above is true and there are no blown fuses and no tripped or bad circuit breakers then the odds are good that you have a problem in your RV's Power Converter.

An RV Power Converter's job is very simple when your RV is plugged into a 120 Volt DC power source or running a generator the power converter takes over the job of providing 12 Volt DC power to your RV from your house batteries and while it is doing that; it also starts charging your house batteries.

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The fact that your 12 volt DC lights and accessories work when you are using your house batteries pretty much eliminates them as being the problem.


Since there are no user repairable parts in a Power Converter, you will need to take your RV in and have it diagnosed and repaired by a Certified RV Technician.

Hope this helps.

Happy RVing

RVing Al

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