First thing to check is the circuit breakers on the generator itself. If they are tripped, it runs but no power. Second place is the transfer switch, which is located where the shore cord and generator wires come together. May be on the back of the laod center (breaker panel) on your Allegro. Other place is where the shore cord attaches to the coach - a black box as RJay described.
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL