Battery Isolation/Charging

[VistaCanada]

I have a 2006 GS Vista Cruiser Mini diesel. We got this MH this past summer, but the past week is the first time we have used it on an extended trip where we dry camp. The house batteries are not being charged by the chassis battery, but charge via the solar I installed and the gen, and charged okay this summer when it was on shore power. I assumed this was a battery isolator issue, so I went digging. I found a solenoid I the left compartment to the rear of the house batteries, and I verified that I have 12v on each side, on side from the chassis, one side from the house. So then I traced a yellow wire back from the third terminal on the solenoid all the way back to under the driver's seat where many fuses/terminals reside. When I finally found the end of the yellow wire, it was actually 2 yellow wires that were connected to NOTHING. If I cross these wires, the solenoid clicks and the batteries are connected. There is a lot of extra wire for these, so I don't know where they were supposed to end up.

So, my question is... What are these 2 wires supposed to be connected to? A B.I.R.D? A BIM? And where should it be located?

I also have a switch on the dash that I assume is for emergency starting to activate the solenoid, but I'm having a hard time following where those wires end up (somewhere under the driver's seat as well).

Any help is appreciated.