just went out and checked. indeed! on my four winds 31e there is non switched power in the vent over the cab. when we bought it i asked about putting a fan there and was quoted $250 just to run wire to that vent! not including the fan r fan install. im glad i found this site!
also checked the kitchen vent and it has the solar wires and a gray/white combo in it with a suspicious yellow tape on it. perhaps this is another circuit form the fuse box.