No Power to Trailer When Hooked to 30A Receptacle

[hwm]

My apologies if this is a question answered in other threads, but I am a newbie at this and I am puzzled... Bought a '69 29F Overlander late last year. Took it out only once and had no issues what so ever.

First time out this year just this weekend. Plugged into the 110V/30A post at the campground, and overhead lights worked, roof fans worked, and the fridge was on, so I thought all was good (again, I'm a newbie). Left it overnight only to return next morning to find no power. Seems all I checked the evening before were 12V items, so everything was running on the battery. So, begin troubleshooting. All fuses and breakers were good & on. Tested park power outlet which was good. Checked power to circuit breaker at the head end and...no power. Checked 110V receptacles and nothing. Checked wiring to inverter and nothing. No power anywhere.

In looking at the schematic, and all I can see, if I am not getting power to the breakers, am I right in thinking the issue lies somewhere between my plug and my circuit box?

Anyway, dragged it home today, had no issues with running lights on the trailer when hooked to the truck. My father tested the trailer battery and it was bad - he said it won't hold a charge. He says that may be why nothing electrical is running. However, I would think that once I plugged into the park's 110V, at least the 110V receptacles would be working.

I am hoping it is simple like a switch somewhere that just turns the whole thing on (newbie thinking). Or a fuse that lies between the plug and the circuit breaker. I can't see one anywhere.

If anyone has any thoughts, please let me know. I appreciate any help anyone can provide...

[J-Dog]

Could it be possible you have an in line surge protector hidden away somewhere? And perhaps it has quit working?
I am mentioning this because last year when I was installing a new converter, I came across an inline surge protector wired into our trailer which I didn't know the previous owner had installed.

[hwm]

Thank you for the quick reply J-Dog - I can't see where one would have been installed. The wire carries into the trailer through the bumper/driver's rear and can't be seen again until it feeds the breakers. Everything is original and unmodified - the only "upgrade" to the trailer is a coaxial cable crudely run through the cabinets. Nothing to be found in the access doors on sides. I'll keep an eye out for something along those lines, though. Again, thanks for the reply.