I would give it another try.. Might be nothing wrong with it.
Opps. re-read the original post.. you did and it's not working.
NOW.. You may not need to junk ALL of it.. The A/C consists of an upper unit and a lower unit.. The lower unit is the part that is in the roof and inside the RV. the upper unit is "The Works". IF you do NOT have a Carrier Air V you can likely just get a new upper unit.. Carrier stopped doing RV A/Cs so if you have a Carrier you need to get an alternative Upper unit.. I think Coleman is the alternative (or Advent Air but I do not recommend the one I choose).
However for future reference:
IF the humidity is high enough and the evaporator cold enough when the cold air comes out of the vents it is so cold that water vapor from the warm air beside it condenses out in a cloud of "Steam" or "White Smoke" NOTE this normally happens only on NON DUCTED A/Cs. not on Ducted ones but it can happen on ducted.
This is exactly the same as stepping out on a cold day and your breath fogs.. Exactly the same thing. Does not mean you've sprung a coolant leak (Actually it does but that's another matter,, said leak is normal)
I used to have a car with "Dealer A/C" instead of factory.. it did this very thing on a humid day, more than once. Kind of scared me the first time but I quickly figured it out. I liked that car A/C worked REAL GOOD.