How to fix Dometic Comfort Control thermostat problems

The a/c wont come on. It's a domestic dual thermostat. The 10 button. We tried switching with new thermostat. We flipped breakers in/outside. I looked at the circuit boards and don't see any burned wires. We just had the whole unit replaced in both a/c. I am not sure if it's a voltage problem. I get nothing on thermostat so it's incredibly hard for me to diagnose issue. Any help greatly appreciated. 5th wheel crusader 2014.