If I'm looking at the pic right, the bottom blue wire from the fuse appears to go to the white wire connector, which has one (maybe two?) red wires coming out. I'm betting at least one of them goes to the back of one of the switches. Whichever switch it goes to is probably what it's for.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10