Electrical questions on 2006 3023

I have a few electical questions after spending all day with my newly acquired 3023..
At front of trailer in 12V battery area, I have two black wires that are not connected to the battery but appear they should be. Connected to the battery there are 2 main wires (+ and - that look to be about 10 gauge) that run back and enter the trailer below the sink area and seem to carry the power to the 12v systems. There is also another negative battery wire grounded to the frame at front. The two unconnected wires are slightly smaller gauge and run alongside the main power cable that comes from the TV hookup (these three are joined with cable ties along lower outside of traielr frame). ALL wires appear to enter the trailer through the same hole near the sink. Any idea what these two wires are for? The end of one of these mystery wires is exposed (insulation stripped) as if it should be connected to something. The other one is simply snipped off at the end. There aren't any obvious items in the trailer without power but I'm new to TMs.

Also, we had the TM hooked up to the 110v home power using an adaptor today. At some point, a fan (or something that sounded like a fan) started running up near the breaker panel (lower bathroom wall). It also looked like the small light furthest to the left on the front of this breaker panel was also illuminated (overload?). Any idea what was making this fan noise and why? Thanks.