Electric short circuit

[progreenery@gmail.com]

I have this '85 New Horizons which has a circuit panel containing 3 circuit breakers. One of which trips when I plug into shore power. I do not know what ANY of the breakers do, except that one of the two remaining breakers that stay on control electric outlets and all 12 volt systems (lights, water pump, heater fan) kick over to the inverter (you can hear it switch when we plug in). We no longer have an Air Conditioner (removed by previous owner), so I can assume one breaker may have been for that. But the other breaker is unaccounted for. Any ideas? Is a schematic available?

 

Also, we changed all 12 volt bulbs to LED. Since then, they only flicker when turn on while on shore power. They work fine off the battery. I'm thinking the problem is with the LED bulbs - not the system. Voltage at socket when on shore power measures 13.6 volts.

[jjrbus]

Not an electrician and have not seen every electrical panel in Toyhome's.  So here is my guess.   3 breakers, now most of the Circuit breakers I have seen over the decades have a number on the handle.  15,20,25 etc.  I would guess the breaker that is tripping may have a 20 on it,  meaning 20 amps, which in general would be for an air conditioner.  There might be some exceptions to this if it was originally a 7,200 or 8,200 btu roof air, then it could be a 15 amp breaker,  but I have not seen any of those so not sure.

If it is a 20 when it left the factory it was a dedicated AC line,  what has happened over the decades by previous owners is anyone's guess. 

What is in place of the removed AC? 

Schematic might be of little use depending on what previous owners have done.

And then the little twist to the story, the breaker could be bad, they can and do wear out. 

Really difficult to diagnose on the internet, so is my best shot.

[progreenery@gmail.com]

Thank you! Good guess without the knowledge and history of this rig. I will look at that - the amperage and whether the breaker is bad. There is nothing in place of the rooftop A/C unit and I have made repairs to the ceiling in that area without any sign of old wiring. So, who knows what he did? Thanks again!