We own a 1995 Toyota Camry. Part of the time, on the hottest days, or the sunniest days, when we need our air conditioner, the most, it quits blowing cold air, and only blows very hot air. When we turn the air off, but leave the blower on, that air is a lot cooler, than the air conditioner’s air. On fairly warm days, or cloudy days, this is not an issue. If we park the car, in the shade, for a while, the air will work properly, again. But if we park in the sun, same amount of time, air is still very hot! Please help!
The fact that the system sounds to be actually supplying heated air - hotter than the ambient air temp - suggests a problem with your blend door. The heat and A/C all uses the same duct work - a little door controls which air gets into the ducts in the car.
The can be vacuum controlled or solenoid controlled. I’d have to guess that perhaps yours is solenoid controlled and solenoid is malfunctioning when it gets very hot. I don’t know this car, but this problem often requires some fairly extensive dashboard disassembly work. Your best bet is probably a local shop that specializes in auto HVAC systems.
Thank you. Hopefully that will fix the problem. Other than that, it is a great little car. 
The timing belt broke on it, a month ago. While our, then 18 year old, son was driving it. My husband replaced it, here at home, and it runs great.