Truth:
Had a brand new. I mean BRAND NEW (Sticker in the window new) 5ER pull into the site in front of me at a COE park a few years back.... She went to vacuum up a bit of dirt her husband had tracked in using the built in central vac.. NOTHING
No 120 volt power anywhere
Post was good (I have good meters) but nothing in the Trailer
So we disconnected teh cord from the trailer intending to see if there was a problem there (next stop on the power train after all is the cord outlet/trailer inlet)
The outlet fell off in my hand.. NOT ONE of the six screws inside the cover had been tightened.
We finally fixed it. Between my spare cord, His knowledge (he is a power plant technician) and mine, and my tool box. we got it all up and running.
But I'd have loved to be there when he returned to the dealer.