Bill,
If I remember correctly, your Expedition is a 38K. On our 2015 Expedition 38K, the outside TV is connected to the bedroom satellite receiver through an HDMI splitter. To watch satellite TV (Dish or DirecTV) on the outside TV, the bedroom satellite receiver has to be on and set to the channel you want to watch. Our Expedition came from the factory with the satellite inputs for all of the TVs connected to HDMI 2. Yours may be set up the same way if it came from the Decatur, Indiana factory.
You might check the HDMI splitter behind the bedroom TV to make sure the input from the satellite receiver and both outputs are connected, one to the bedroom TV and the other disappearing into a cutout in the wall on the left side of the compartment. If those connections are okay, you can check the connections to the back of the outside TV by removing the felt covered thin plywood panel behind the kitchen sink plumbing. It is rather difficult to remove, but it can be done. It isn't screwed or nailed to anything. It is held in place by its snug fit. Working the bottom out first is probably the easiest way. Once it is removed, or at least moved enough for you to see the back of the outside TV with a flashlight, you should see an HDMI cable connected to one of the HDMI inputs. If that also looks good, and you still don't have a satellite signal on the outside TV, you should still be under the one-year "wall to wall" warranty. Let an authorized dealer take care of it.
If they are within reasonable range, I recommend the Decatur, Indiana REV Recreation Group Service Center over an authorized dealer, but the wait for an appointment is apt to be long. There is also a service center in Coburg, Oregon if that location is more convenient. I don't have personal experience with them but they reportedly are as good as the exceellent folks in Decatur.
If you have the upgraded satellite antenna, I like the Dish Hopper solution. Unfortunately, it isn't compatible with the Winegard Roadtrip Mission antenna that comes as standard equipment on the recent Expedition and most other Fleetwood models.