The receptacle should be hot all the time from the 120 volt AC power distribution panel.
Some rigs have this receptacle ran through a GFCI receptacle. Locate your GFCI receptacles and check to see if one is tripped.
Have you reset your circuit breakers? Turn off all circuit breakers applying light pressure toward off. Then turn on main circuit breaker if equipped, and then each of the branch breakers one at a time.
Get one of the small normally yellow circuit analyzers that plug into the receptacles to identify what is issue.