I'll bet Money that it's the Gear Box...
I'll bet if they used the drill motor and flexible attachment to run it, there would have been the tooth skipping, popping noise that way too many of us have already heard. If the motor run, it runs. If it's over loaded, it pops fuses. If they think that this is a motor, it will be the first one. All the problems so far have been the "Weak" gear box.
Maybe Forest River will make them replace the gear box first. Both are a pain to change, so its not a "I'll change the easy one first" fix. I tend to lean towards the tec's inability to look at the whole problem.
2014 FR3 25DS (Bought 2-22-2014)