Are you mistaking the circulation fan for the AC coming on? If your heat and AC are ducted through the same duct it would explain it. Or they may have out smarted us all and followed the logic that automobile designers of late follow. When you turn on the defrost the AC comes on to take the humidity down! Check the manual for the heating and cooling and the thermostat. The assemblers of RVs do not always do a great job of integrating things!
Neither do they cover the warranty of individual items while the rigs warranty is generally the shortest. What a racket.
RUSTIC is good.
Kudos to those who make Local, State & Federal Parks & Campgrounds possible and to those picking up the slack by Providing Private Campgrounds.