I just had my AC checked and recharged.I drove for a while cut the car off came back one hour later and the AC would not blow cold air again.
Air Conditioning on 1990 Toyota Corolla
check the condensor blower motor to see if it's working. also check the sight glass for bubbles. you may have a freon leak.
I would have the system rechecked by the shop that serviced the system for you. If the system is low or out of refrigerant and they cannot find a leak then I would recommend having them recharge the system and to put some dye in it. This dye will help them locate where the system is leaking from. It can be very difficult at times to find an A/C leak since refrigerant is a gas at atmospheric pressure. The dye will leave a residue that can be seen with an ultra violet light. A common place for an A/C system to leak is at the service ports. New valve cores can be installed to repair this problem.
Could be that there is a leak significant enough to lose charge in an hour. Or there could be an intermittent electrical fault. I would have the system rechecked.