The unit was installed 3 years ago. It was never started until now. I have changed the filter dryer, vacumed, and I opened the txv inside the cased coil. I have sucked the refrigerant back, and vacumed 3-4 times, but the liquid line stays cold and the suction line stays warm. I do know the compressor is on. I just don't know what to check next.

After sucking freon back into unit, and vacuming 3-4 times, and checking the txv in cased coil. The compressor is on and running, but the liquid line is still cold and the suction lines is warm. What should I try next?

What are the readings on your gauges? You have gauges hooked up right your high side head pressure is how you know if you have the proper charge.

If you have a heat pump unit it, maybe the reverse valve is stuck on heat, reversing the process.Tap it lightly with the butt of a screw driver and put the thermostat on cool.That maybe the problem.

Where is the liquid line located on the condenser?