2011 Ford F-53 owner's manual is here
. Page 66 and following says the trailer turn/stop signals are fed from fuse #22 on the Passenger Compartment Fuse Panel.
Winnebago Wiring Diagrams for 2011 Adventurer 35P are here
. Front End Wiring Installation (link here
), sheet 2, Zone C-4, Detail BA says the Ford passenger Compartment Fuse Panel is mounted above the Winnebago circuit breaker panel that is in front of the driver's left shin.
Operator's manual for your coach is here
. Page 3-15 in the manual (which is page 39 of the Adobe PDF document) has pictures of the Winnebago circuit breaker panel that is by the driver's left shin.