First of all you need a set of manifold guages. This will be able to show you the working pressures in the system. A/C works under the "expansion of liquids theory". When high pressure liquid refrigerant goes from the high side through a expansion valve or orifice tube where it is converted to a gas, in the low side. There are many reasons your system may not be working. Get help!! You could hurt yourself, because of the high pressures involved and the chance of frostbite playing with liquid refrigerants.