Why does my ac only blow hot air?

just turn your a/c on high and as cold as it can go. look at the compressor see if it engages... note it will turn with the belt but there is a clutch you should be able to see the difference on the front of it when it turns and when its not. make sure its turning not just the pulley turning from the belt. and then check the lines. ur a/c lines should start to get very cold or atleast some what cold. if they do not then it may need more freon. some times you can have just enough freon to have the compressor to run or cycleing off and on yet its not enough to get cool or for you to feel it. so you have to add more. even the walmart diy gages and all that will give a reading that its full when its not. if u check it when engine is off then it will say its full cause its not flowing through the system. if u check it with the compressor on like your suppose to then it should give a lower reading unless it doesnt have anough freon in it to push through the system so those diy walmart gages are junk. they dont tell u much. id say try adding another can of freon to it with the compressor running. it has to be running when u add freon. it has to have enough in it for the compressor to move it around and it has to have enough in it to work right or compressor may cycle on and off but thats not always the case. just attempt to add a lil more to it and check to be sure the compressor is turning when u turn it on. id say its still too low to be honest if it holds a charge not leaking then id bet all money on its still low. those gauges always lie cause it depends on if the freon is moving or sitting cause it is just measuring the psi pressure so if its not moving and not much in the system it will give higher false readings. and as i said if there isnt enough the compressor cant move it but also the compressor has to be working and turning on as well. engine must be running when u add and check it.