When a DirecTV satellite receiver does not get a signal from a satellite, it sends an error message to the screen informing the viewer that it's searching for a signal. This does not mean that the dish is moving. It only means the electronic circuits are checking for the presence of the signal, and will continue to do so until a signal arrives. Your dish should have been properly aligned at installation by a DirecTV technician. The loss of signal could come from several causes.
Check the weather outside. A severe thunderstorm in the path of your satellite signal can block it completely, even if it isn't raining at your location. A light rain should not cause signal outage. If it does, call DirecTV and ask for a service call to realign your dish for a stronger signal.
Check the dish for damage or being pushed out of position. If a heavy wind has bent or ripped your dish off the mounts, you will get the warning until it is repaired. If a branch has fallen on the feed horn and broken or bent it, you may not get a signal. Ice or snow on a dish can also block the signal.
Check the cable connection at the input to the receiver and at the dish. Follow the cable looking for breaks, cuts or a crushed cable, which could have an internal short. Remove the connector and look for physical damage, corrosion or water. Replace the cable or connectors if necessary or call DirecTV for service.
Look in the direction the satellite is pointed. If someone has built a house or building, or constructed a water tower in the path, you signal could be blocked. Also look for trees that may have grown into the path.