I have a 67 Caravel
. Not sure about the wires near the breaker panel. I have an aluminum romex type 2 wire cable that comes out of the wall just forward of the breaker panel that feeds a light mounted on the other side of the bulkhead. The light shines down onto the couch (gaucho, whatever)area across from the stove. In the 67 Caravel
that I have, the three wires and the inverter like box located under the couch just forward of the bulkhead is a low voltage transformer. One set of wires (black, white and ground) is a 120 volt lead from the Main Panel to power the transformer. The other sets of wires (two romex cables containing white and black wires only no ground) are the output wires from the transformer. They feed low voltage AC power to the lighting and fan circuits (and possibly water pump not sure about this). On my trailer one of these circuits provides 12 v ac power to the fan over the stove and to the overhead vent fan (no longer there). The other circuit provides 19 v ac power to the interior lights. It appears that the fan motors that orginally came with the trailer will operate on either dc or ac power. The lights will of course operate off of either ac or dc. I noticed that the lights were much brighter when operating off of shorepower. I now know why, they were operating at 19 volts rather than the twelve volts provided by the battery.
The switches on the control panel in my unit, were used to switch the light and fan circuits from battery to transformer when connected to shorepower. It does not appear from what I read in my owners manual and from the wiring diagram that the 1967
Caravel came with a univolt type converter. The ac transformer was used to minimize battery use while connected to shorepower. No provision was made to charge the battery while attached to shorepower. The battery was charged by the operation of the tow vehicle.
Be advised that the above description is for the configuration on my California built 1967
Caravel. Your configuration may be different. Hope you find something useful in the above. By the way, I have completely reconfigured the wiring and have eliminated the transformer and installed a converter to provide dc power to all circuits when on shorepower and to charge the battery as well.