Same thing happened to me this summer, I by passed the transfer switch and tried again , still no shore power, every time I plugged in the power cord it would trip the breaker on the pedestal. After a couple of hours of tracing wires looking for a problem, I found out that the #6 or #8 ground wire was on my neutral bar on my breaker panel in the coach. I removed the ground wire from the neutral bar and everything worked fine. Put the ground back on the neutral bar and pop goes the breaker on the pedestal, so removed the ground wire again , everything worked fine. So for 3 days we camped with power, and no more problems.
Just so happened that the next morning, my wife saw an electrician working on another pedestal across the road from us, I went and talked to him, he was the electrical contractor who's company did the work in the park ( BTW this was an older government park just upgraded this summer) and the electrician told me they have been having all kinds of problems with newer class A motor homes tripping breakers. He said that the type of breakers the government requested are to light to handle the load when these units plug in, and he mentioned the grounded neutral bar.
When I got back home, I reversed everything I had at the park, everything back to normal, plugged back into my house, no problems at all. I was happy, after just purchasing a brand new motor home and only 3 months old , I was worried that I had bought a unit with major problems, and it would be in for repairs before I had a chance to really enjoy it for one season.
Hope some of my story helps
