The can I used to recharge it was 1/2 full. Could it still need more. And How do I know.
I just replaced the ac condensor recharged the system but it will not come on. on 2008 Kia Amanti
YOU NEED TO HAVE THE PROPER GAUGES AND EXP TO REFILL A/C SYSTEMS NOW DAYS. SOUNDS LIKE YOUR NOT SURE OF WHAT YOUR DOING AND THATS OK BUT YOU CAN CAUSE OTHER ISSUES IF THIS IS DONE WRONG. SEEK HELP FROM A MECH. PLEASE
And if this helps your compressor is controled by a control module. I looked at wiring diagram to see if a low pressure switch is on your system. It did not show one. Most A/C systems have a pressure sensor to protect the compressor if it has a loss of pressure. A/C systems require a very specfic charge to work properly. It could mean you do not have enough r134 in the system to allow the module to turn compressor on. If I had your car to work on the next step would be to scan for faults in A/C module and inspect all wiring and sensors accociated with a/c system.
These guy's are right you need to have the system evacuated to remove the oxygen in the system and then new freon can be installed by using the proper gauges, Have the system recharged by a qualified shop and you should be fine