Do the yellow wires end in the vent location, or are they circuits going somewhere else? If your wiring is similar to my '06 Itasca, the white wire should be a ground wire and the yellows are positive. You should be able to hook a tone generator to the wires and trace them back, probably to your house fuse panel.
Dan & Ro with two Rescued Boston "Terrorists"
2015 Tiffin Allegro RED 38QRA
Previously '06 Itasca Sunrise 35A on a W22 Workhorse
'12 Jeep Wrangler Sport and/or '08 Honda Goldwing