Follow-up: Just picked up my pickup; though I probably won't hitch up and test until Thursday, everything seems to be working the way it should
. When I hooked up to the trailer, I had a signal instead of the E1 message. I am so excited!
I have contacted UHaul and explained the situation and that I will be protesting the installation charge. I have contacted my credit card company.
The controller was fine. It just had to be "re-wired, front to back". He said it was a mess.
I am glad to put this to bed and get on with my travels!