What model and chassis is the coach on? I would think that all of the class A's would charge the house battery bank off the alternator. If it is a class C it may not. You might consider asking this question in the Gulf Stream Owners forum farther down the main forum page.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7