The rig should come with a booster already installed, somewhere there is a wall plate with a push button and a light, mine is in the W/D closet in the bedroom. There would be a couple of things that could cause your problem, but the most probable is the antenna pre-amp power supply is on the same 12volt circuit that the bathroom lights are on. Another possibility is that there is probably LED lights installed in the bathroom and they are emitting RF that is interfering. In my 2012 Pinnacle, the connectors on all the wiring were done better than any RV I have ever seen, so hopefully Jayco is still using the same connectors and tools to terminate the cables. If connectors are not terminated properly, an improperly done connector can allow interference into the system. How far are you from the transmitter? That could also be a factor. I had OTA issues with my original Winegard Antenna, so I installed a new King Controls Jack antenna with better results.