I dont know why but my ac blows cold. then it starts to stop blowing cold then when i drive it starts to get cold again. It does this alot does anyone know what it could be? I took it to the ac shop and the freon is full can someone please give me any ides of to what it could be? Thank you

 

There are so many possibilities. Some of them can be sorted out by us shadetree mechanics but others are best left to a A/C specialists.
Make sure the condenser is clean. Make sure the radiator fan goes on and stays on when the A/C is turned on.
Sometimes there is a problem with the blower switch. Make sure the blower works on all speeds, and that the A/C light stays on when you change the blower speed.
Check if the A/C clutch is working correctly.

An A/C technician should do more than just check the low side pressure. He should also check the high side pressure.

Sometimes an A/C can be evacuated with a vacuum pump so that moisture annd other contaminants are pulled out of the system. A refill after that may fix it. But I would give it to a specialist for that.