It is likely the four dead receptacles are multipled together and either directly fed from one 15 amp AC breaker in the main panel or sub fed from a fifth (possibly working) receptacle also on that same breaker. So Thor likes to save money and would likely feed all these receptacles in order from the one breaker and so the closest dead receptacle to the breaker panel might be a good one to open and check for good tight connections coming from either the AC feeder breaker directly......or from a possible fifth working receptacle that I would guess might be located logically between the breaker panel and the first closest (of four) dead receptacles. You might also need to open the breaker panel and check that the 15 amp breaker hot and neutral wiring is good and all connections are tight. Make sure your shore and gen are off for safety, since you are just checking for broken or loose connections at this point.
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