switch on the receiver/dryer to test. Not sure what cover that is. Key item to diagnose is rapid clutch cycling. Computer is turning off power to relay due to some input. Cycling correlates with signal on pin 42, the TCA. Bypassing the TCA still did not improve things much.
Air flow blending doors, coolant valve to internal hot radiator (heater core), occlusion of evaporator and a failing evaporator temperature sensor (TCA) must be involved. No doubt in my mind that the problem is inside the air boxes.