gospelbike, welcome to iRV2.com. We are glad to have you join us here and we look forward to reading of your adventures and experiences.
It does sound like you need to start at replacing the batteries. If shorted out they could even blow the fuse(s) on the convertor charger. You need 12 volt DC for almost all appliance controls; the air conditioner is included. As long as the converter charger could supply this, you could limp by, once you loose the charger/converter you have no control voltage to operate the air conditioner in this case. I would suggest you install new batteries & check the convertor for blown fuses or triped ciruit breaker in the 120 volt AC distribution panel. Drain the battery bank down a litle; check the voltage of battery bank with out power applied, plug in or start generator and remeasure the voltage at the battery bank. You should see an increase in voltage (13.8 approx.) if the charger is working. Good luck and keep us posted.
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