First.. Carrier is no longer in the RV A/c BUSINESS
But try disconnecting both 12 volt (your house disconnect is good enough) and 120 volt for like a minute or two and try again. If that does not work look for a blinking RED led up inside the unit (you can see it thrhough the filter if the filter is not in serious need of cleaning, if it is not blinking I beileve you have a power issue. check both 120 and 12 volt to make sure it's arriving at the A/C.
I have spare blower motor, blower, fan and start capicator somewhere in my basement.
If you end up replacign the thing... IF the problem is entierly in the rooftop unit, ADVENT AIR and I think Coleman make drop on replacements for the upper unit, no need to change the duct adapter or the inner (Ceiling) unit, no re-wiring (Well very slight, will describe the Advent adapt-a-kit) and you use the same controls.
IF it's the controls that are bad.. You gonna need a new one, keep old rooftop as apare.
The Adapt-a-kit
Consists of 4 bolts and two wire harnesses.. The only "Rewiring" needed is to open the control box (part of the ceiling unit) and remove one 2-wire lead and the attached MOLEX socket and replace it with the matching Advent Air lead and socket. You then plug a "Y" adapter (The other harness) into the two jacks on the Carrier control box and plug the rooftop unit into the "Y"'s socket.
As I said I think Coleman makes a drop on replacement as well. but I did not buy that one, I got the advent air. 15,000 btu worth. I'm very glad since I can only run one A/C in this park (And they both draw the same amount of power)