Assuming a 2015 Ford fuse record still applies to your “likely” 2014 F53 chassis......you could try position 17 (20 amp)|on the passenger compartment fuse panel under dash, near drivers lower left foot somewhere. If that is not the correct fuse, scroll down on the attached link and you may find it on the fuse record somewhere. I am also not sure if Thor installed their own fuse panel to replace the Ford fuse panel, which they seem to do on some coaches. Hope this works for you.
https://www.autogenius.info/ford-f-5...e-box-diagram/
On F53 there is typically a PDB fuse panel mounted on the firewall in engine bay near the engine air intake box.