2 replies, and already conflicting information...
In re an owners manual, dont waste your time. It's not like a car or truck manual... it's simply general info, and is not model specific.
The problem answering a question like this is that different rigs are wired differently from the factory. Some have separate cable & satellite inputs... others don't. The majority just have a cable input... which can be used for a satellite dish.
Pictures work wonders on this site. By showing us what you have, we can assist you better.
You mention you have good cable, but over-the-air (OTA) not so good. You probably have an OTA antenna amplifier switch somewhere on the RV that needs to be switched ON when you wish to watch OTA channels. But, take note that... when watching cable channels, the amp needs to be OFF. I'm guessing it's currently OFF right now, since you state the cable reception is good.