a/c
While those posts could be right, there are a lot of other possibilities. I would check that first, I hope that it is the right answer as it is the least problem to solve.
What you give isn't a lot to go on, if it should be that the freeze up isn't the issue. So try that first, then if it doesn't work give more information. Was the compressor running or had it stopped and only the fan was turning? If you shut the system down for a time, what happens when you attempt to restart it? Does everything sound normal? What is the voltage that your RV is grtting from shore power? It should be at least 108V for things to work properly.
Also, what make and model of air conditioner? How old is it? Do you have ducted air?