The salesman solenoid will be located fairly close to your house battery bank. Mine is located in the rear electrical compartment which is adjacent to my battery bank.
The is a large fuse for the 12 volt circuit, probably 200 or 300 amp, mine is 300 amp.
On my coach there is also a Klixon autoreset circuit breaker.
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi