The 13.5 A/C will not cool rear bedroom on DP. What to do?

I have a 13.5 acnd in my bedroom and could use the area to store hanging meat. It will get cold. I stick a dial thermometer in the outlet and get a reading between 40 and 50 degrees. I use it and a fan to help cool off the front of the coach. I think I would be checking to make sure the acnd unit was working properly.