Let me guess. 50 amp RV?
The reason I say this is 50 amp rigs have two power "legs" and you may have lost one leg.. tHIS CAN BE DUE to a tripped breaker (main) in your RV or at the park pedistal or at the park main service box (Distribution panel) or a bad wire or several other issues.
If your RV is properly wired then when this happens ONE A/C will work, the other will not.
Page 2: A non-joke I often tell is this, Many RVers have a few screws loose.
Here are SOME of the loose screws I have found in my RV.
Power inlet: (one screw on one leg causing what you see)
Circuit breakers.. Several in my RV one took over 3 Full Turns to tighten (ouch, fire hazard in fact).
And on another rv ALL SIX screws inside the Marinco outlet (And on still another just one, the neutral).
And I've seen bad connections in the park power pedestal and main distribution panel.
And you must remember when reading this.. I DO NOT DO THIS FOR A LIVING... If I did, I'd have much larger numbers of rigs I've worked on.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times