If you are faced with an in-motion system that refuses to follow the signal while moving there are three things that may cause this problem.
First does the unit have a GPS antenna? If not it may not be an in-motion system. Look closely at the label on the cover of the electronics housing under the dome. It should tell you if you have a in-motion or "tracking" system.
Second a Winegard in-motion system may be installed either facing the front of the coach (A setting) or to the rear of the coach (B setting). Once the unit is installed the switches in the electronics housing must be set to match the installation option used. Switch #1 up for option A and down for option B. The unit is designed to only track while moving forwards. The switch setting tells the unit which direction “forward” is.
Finally under the dome, inside the electronics housing, there is a small circuit board that connects to the main board by a mini USB cable. If this cable gets disconnected, the unit will not be able to track the signal while in-motion.