264BHW AC question

[Fdnavy]

I have a 2016 Jayco 264BHW travel trailer. It does not cool well all. The compressor kicks on and runs for a few minutes and then turns off but it never cools the camper down enough. The air when running is ice cold. Today I measured it at 42 while the compressor was running. I opened up the unit and found the foam divider separating the cold air and the return was knocked over. I fixed that and taped it with alluminum tape hoping that was the cure. No luck. Compressor still runs for only a few min at a time. Any ideas as to what would cause this? Then I read someplace that the thermostat may should have an adjustment screw that sets the stop for the cold air knob. Can anyone tell me how to access this thermostat? I’d also like to know what model the ac unit is and what model the control panel is and if anyone can tell me how to access the thermostat (the box that the temp control knob moves) I know it’s the 15000 BTU unit but that’s all. I do not have a separate thermostat. Only Knobs in ceiling mounted return. I’d like to try and see if this stop screw helps. If not I’d like to replace the thermostat before having to pay a service tech to tell me I need to replace the entire unit.