Just a head's up, your inoperative outdoor outlet may not even be hooked up. I bought my trailer brand new and found out on our first outing that only one set of outlets worked, and the other set was completely dead. It was fixed under warranty, and the service tech said it wasn't even hooked up in behind, and that it "may" have come loose during delivery or may not have ever been wired up properly. Either way, I gave the dealership sh!t for not catching it on the PDI.
I personally have not seen a trailer that has outdoor outlets controlled by a switch... I'm willing to bet there is a problem with it, or as Jagiven said, a tripped GFI.