Referring back to the first post, there is no point in arbitrarily replacing the interior temperature sensor. You can so easily check if it's working through diagnostics.

When your compressor is running and you are getting warm air through the vents, the only way I see the controller possibly being a problem is if it is opening the monovalve and flowing hot coolant to the heater. You can run diagnostics and verify this is not happening and that the heater is at roughly ambient temperature.

Your problem is more likely low refrigerant or a bad expansion valve. If you see bubbles in the site glass of the receiver, then your A/C needs a charge and may have a leak. And if you measure low and high pressures with a set of gauges you can diagnose both low pressure and a faulty expansion valve.

It takes about two hours to remove and replace the expansion valve.