Let start fresh here. Before you have any concerns about the antenna on the roof you appear to not have a proper connection between the TV and the satellite receiver and that's what you are looking for help with.
Are you using an adapter to convert the Yellow, Red, White RCA cables from the DirecTV receiver to a coax output? I assume that this is the unit that requires you to use channel 3/4 on your TV. If so, this is also usually powered and needs to be plugged in. From that converter the first thing you want to do is run a new piece of coax directly to the back of the TV and do a new channel scan with everything connected and powered up. Be sure the TV is set to Antenna and NOT Cable before you scan and it will find analog channel 3 or 4. This will get you a good starting point.
Once you have the direct connections working you are going to need to work backward to make the necessary adjustments.
If you are trying to see this signal on multiple TV's in the RV then you should have some kind of a switch box with buttons labeled Ant, Cable, Aux, ect. If not then the coach may not be set for sharing and you are going to have to modify some wiring by adding an A/B switch but I need to know more about your setup. If you only need the satellite TV to show up on the TV where the receiver is located then just install an A/B switch that would allow you to select the current OTA/Cable option or push the switch and watch satellite TV.
What I post is my 2 cents and nothing more. Please don't read anything into my post that's not there. If you disagree, that's OK.
Can't we all just get along?