On my rig, it has an intermediate converter. It is somewhere after the battery and before the final converter. It has two 40 Amp fuses in it. They are on on end. It is about the size of a carton of cigarettes and has an aluminum case. Basically, these fuses offer protection from things like this that can happen. Or from reversing polarity on your battery.
Replace these fuses and you'll be good to go. But the problem is to locate this component. Probably deep in the bowels of your trailer. Might need to remove the coro-plast to find it.