It looks like you are onto something, Mike. I looked into the space behind the fuse panel and, viola, there are a half dozen white wires converging into a wire nut, from which a three foot length of white wire emerges which is long enough to reach the fuse panel but is not connected to anything -- just a stripped end resting on the floor. There is also a bare copper ground wire emerging up through a hole in the floor which also is not connected to anything. I also noticed that the ground terminal on the back of the fuse panel does not have a wire connected to it.
So, does the white wire go into the empty spot on the C terminal block?
By the way, if this is the problem, I don't understand why the 12V appliances all worked fine until I changed out the trailer connector today.
Thanks again, Mike, and others who have responded.
