I have a Goodman AC. That was installed about 2 months ago. This unit is for the upstairs. I had someone check the temp coming out of air vents with a digital reader. It was about 72 degrees. Then we checked the unit downstairs and it read 52 degrees. Big difference. They checked the freon and it was @ 75 which the guy told me it was full. The pipe outside is cold. There isn't anything frozen on the coils. We set the temp @ 70 and it just keeps running but doesn't cool. If there is anyone that might have a suggestion please let me know what I can check next.

That is a new unit and should be under warranty by the contractor that sold and installed the unit. The unit was sold and installed by the contractor and it should perform and cool the area. If they will not fix your unit so it works then take them to small claims court.