Seen this in a 2014 Tiffan. Of course you stumble across it when it's not working. Have heard Tiffan has had a lot of issues with the box.
Not sure why anyone would Engineer or Design this method. Wire may be cheaper and easier to run but the connection switch is another issue.
There are many boxes out there and they do have to be powered. I believe on Both ends creating another heat source. The Tiffan had a 12 volt fan with them.
Here is one box.....
https://www.walmart.com/ip/Cables-To...eiver/39323004