Originally Posted by overlander63
The fuse, if there is one, is located upstream of the brake controller in the tow vehicle. It's mainly to keep the tow vehicle's wiring from doing its own impersonation of Chernobyl in case of a short. There isn't one on the trailer.
That's exactly where the missing fuse was in my case. As I originally said, the van was made ready in every way, except for one small detail: no fuse in the position in the van's fusebox that was for the trailer.
What a relief when I found that out. That, and I immediately wondered how the installer tested the wiring...?