The cable/antenna connections should be in the ceiling above the television mount. One of those plates should have a small push button. When you press it a small green or red light should come on. When the light is on, the booster is on and the TV is on antenna. When it is off, the booster is off and the TV is on cable.
2014 Coachmen Catalina 253RKS
2017 F350 6.7L DRW CC LB 4x4 Lariat