Do you have the antennae booster turned on??
You need to use the 12 volt booster (typically where the coax attached to the wall) to get signal from the roof. Turn off for cable use.
You may need to "tune" the antennae to local stations also. Turn antennae and re-scan TV for local stations. The signals are all digital now, and more directional than the old analog signals were.
Steve and Vicki
2011 Dodge 3500 CTD Outdoorsman
2013 Columbus 320RS-ITS HERE!!