Ok, so you are running the generator and using both AC's while traveling, right??
Check the vent on the firewall in front of the passenger seat to see if hot air is blowing in while moving. I don't know what floor plan you have but on mine, 40BPD, I put a latch on the sliding door going to the bath/bed room to block out the heat from the engine and just use the front AC. There is a tremendos [sp] amount of heat that comes from the engine.
2000 Monaco Diplomat 40PBD
2012 Grand Cherokee Limited
2008 FatBoy, three spoiled Great Danes and a cat.