Refrigerator in slide out not cold enough

I have been doing a TON of reading on this the last few days. The problem with the refer in the slide is lack of airflow. The non slide units have a vent to the roof that allows cooling air to draft up and out.

Have you added extra cooling fans to the box? Did you check to see if there are any air flow restrictions?

If you are set on going to a residential get an inverter to run the fridge so it will stay running when you are going down the road

Chris