I had a MH with 2005 FL XC chassis, there was a fusebox,4" x 4" in the basement on the passenger side by the rear wheel with all the fuses for the
7 pin trailer connector.
Siggy & Ursula.
2011 Newmar DSDP 4020 , (No DEF, 07 emission),
FTL XCR Chassis , Cummins ISL 400 HP