First Post, Out of Frustration over Dometic AC

First off, glad to have found this site as it appears to have lots of good information from fellow RV'ers. We are currently living in our Forest River Wildcat 5th wheel for going on a year now (new home being built). Ever since buying this camper new in '16 we've had issues with the AC, the thing seems to start/stop alot while it's cooling, I realize it should "shift" the fan to Hi if it's too far out of range on the thermostat but it doesn't seem to do that very often, it will shut the fan off (not compressor) several times in the course of a few minutes or it will just run flawless all day, never know. Well, earlier this year the thing wouldn't come on at all and I just figure it bit the bullet, so I bought a new one and installed it, guess what... same thing but at least it ran. A few weeks go by and it refuses to start again, T-stat is set as 72 and it's almost 90 in here, I call the dealership and they tell me that more thank likely either my T-stat or control box is bad so I drive 2 hours to get a new control box and T-stat, install it and and same thing. So now I'm thinking I have a good AC unit thrown into the dump pit and something else is the problem since I just spent $1600 on a new AC/Control box/T-stat. What else is there besides wire running from the AC to the T-stat.??
Right now we are having to basically reset the thermostat each time it shuts down, it will run and satisfy the thermostat and when it shuts down it will not restart without doing that, which really sucks at night!!! During the day while it's so hot it just runs all day.
I'm at a loss!! I'll try and search the forum for more tips.