Two a/c's are not enough for large 5th wheels in the summer heat (95 plus degrees)I also had mobile tech come and check the main a/c, he said it worked like it should. I installed a 3rd a/c in the rear vent of my 38ft fifth wheel. It did take some time pulling wires using a fish tape. But well worth the time and effort. I installed an a/c that was not ducted and find that it works much better. All the air goes dumps in the room with the a/c. On 50amp I can run all three. On 30amp I can run two, we always pick the 3rd one that dumps in the living area( I have a rear living plan). Good luck, you won't be disappointed with a 3rd air.