My advice would first to be ensure there is 12V power to the unit. change one thing at a time fuse first then move on to something else. I don't know the unit you are referring to so this is a guess on my part.
Jake my sidekick (yellow Lab) 10/04 - 05/20
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho