Fan Continues to Run

Hi, I recently tried to install nest in my condo with my trane heat pump system (Trane Axiom Water-Source Comfort System Model GEH/GEV). We have a brown Y-wire, green G-wire, white O/B-wire, red R-wire, and blue C-wire. I've attached these all to the corresponding ports on the nest. (images attached) The heat seems to be working fine, but the cooling does not work properly. Our home is typically around 78 degrees, and we set the thermostat to 73 degrees. It will cool to 75 degrees, but it never gets any lower than that, the fan never stops running, and it typically goes back up to 77 or 78. Since the fan never stops running but the house doesn't get any cooler, I assume that the condenser turns off for some reason. Once it goes back up to 78, if we turn the nest off and back on again, it seems to reset the condenser and it will go back down to 75. But then the cycle repeats. We have to reset the nest every 30-60 minutes to keep it at 75, when we would ideally like it to be 73. We've tried connecting the red R-wire to both the Rc and Rh terminals, but it doesn't make a difference. These are supposed to be internally connected anyway. We've reset the system several times but that doesn't help. We also tried disconnecting the C-wire, but that caused the unit to shut off completely after about 5 minutes with an error message that said there was no power to the Y-wire. We disconnected and reconnected the Y-wire several times, the system would start again, but turn off again with the same error message after 5 minutes. We ended up reconnecting the C-wire and that issue stopped, but we still have the problem with the house not completely cooling down, and then re-heating back up to 78. Are the wires hooked up properly? Is there anything else we could try?

I have an older nordyne 5ton package heat pump. Model number unknown as it has faded off. The unit worked fine all winter, but upon switching to cooling it seemed to work for about 30 minutes then the compressor stopped and both fans kept running. I removed the cover while still running and the compressor was very hot to the touch. If the unit is completely cool, the compressor will come on as normal but gets too hot to touch with bare hands in just a few minutes. If it is not completely cooled down, the compressor will not come on but the fans do. When it is running, the big line on top gets cold and the smaller one below is to hot to hold. Both of these "measurements" are from about 6 inches from compressor housing. I did replace the dual capacitor as it tested weak. No change. The compressor is no louder than it has been when running. The discharge air inside does not seem as cool as it has in the past, but that is as perceived by my hand on the vent. Any suggestion for diagnosing this will be greatly appreciated.