Its a 2002 ford mustang gt, i have tried the refrigerant and the level is fine and wont take any. So here is the problem, my air isn't blowing cold. It blows just slightly colder from the drivers side vent but not much colder. the compressor is squeaking a little but i think it is working because when the refrigerant gauge is on there the needle moves when the compressor kicks on. i think there is a vacuum hose broke somewhere or some kind of vacuum controlled valve isn't working. i just dont know where these valves are, or what they are. i have looked under the hood and couldn't find any vacuum lines that were broken. any help would be much appreciated!!!