CumminsDriver wrote:
If closing the main ceiling vents doesn't help, check the panel inside the AC unit which keeps the supply and return air separated. You'll have to remove the AC cover attached to the ceiling to check this. Mine had fallen over and the supply air was being drawn right back into the unit. After fixing this the air flow was greatly increased to the rest of the trailer.
Rich
X2
This if you draw too much of the cold supply air into the return the unit will freeze up! I used aluminum duct tape to seal return from supply, took about 30 minutes.
Your AC should be able to reduce inside temps 20 degrees.