Our '16 doesn't have the extra switches in the basement. The fuse I found was my pulling the switch off the wall and pulling up the exess wire to expose the inline fuse.
You probably need to pull the switch to see if you have +12V and that the switch is good.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top