My a/c was working but hardley blowing so we put some of that free-on in a can that u buy at walmart and then it just started to blow out hot air. now it just doesn't blow out cold at all .

Several things can make the a/c blow hot air. if the a/c was working but barely blowing then you may want to check for a clogged cabin air filter(it is behind the glove box in the a/c box). since the a/c is blowing hot all the time now, try releasing the freon out of the system or have it recovered into a recovery machine. you may have OVERCHARGED the system and the high pressure switch is keeping the compressor from working.the best thing to do is have the system pressures checked to see if the low side is 35-45 psi and the high side is175-225 psi with the compressor working. if the pressures are not within these parameters then there is another problem.