Loose 12v connection to Front Shell

[wbmiller3]

Apologies in advance because I'm sure this has been covered before here, but I can't find it.

On the last trip, I discovered that we have a loose connection on the 12v power to the front shell. From wiggling the wires strapped to the lift arms, it seems to be on the wire that leaves the lift arm and then goes up through a hole in the bottom of the trailer.

I did not have time to research it further then, but now I need to get on it.

I sort of remember reading here that there is some kind of connection panel or something that is reachable through the fridge vents. If that is true, that is likely where the issue is.

Looking at this diagram

I'm basically looking for where the highlighted wire (which runs up the lift arm) connects to power. Does anyone know where it joins up?

Thanks!