The Dometic roof air conditioners require 12 volts to power a relay circuit board. If your 12 volts was low, the automotive style fuse on the circuit board may have blown due to too much current being drawn. The circuit board is located in a metal box that is visible when you have the air filter removed. Be sure to disconnect 120 volt power before opening the box to check the fuse, as the high voltage is also in an adjacent section of the box.
2010 Georgetown 373
2013 Jeep Wrangler