1993 Ford air max camper Shut down when it gets hot

sounds if your ac is low on gas charge , this is why when you put it in recirc it gets cold

You have to add 134a refrigerant while the engine is running and the A/C is on max with temp setting at lowest level. Without the proper charge in PSI, the compressor will not kick on. If the pressure is correct under those circumstances, You either have air in the system ( take it and have it pumped down then refilled) or the compressor is bad.

there are few things you need to check out:
1. if the compressor is overcharged it will shut down and you won't get any cool air
2. the thermostat for your cooling system is bad
3. the link to adjust the temperature is too short (did you feel the switch loose when changing temperature from hot to cold)?
hope this helps.

If you flushed the cooling system, you probably got air in the coolant lines. It takes a while to remove it. This is done by running the car in park at 1500-2000 rpm with the heater on max and the fan on max. when the heater blows hot air you are almost done, if it doesnt, shut the car off as soon as the temp gauge is half way! Let it cool down and repeat.

There is a Flap on heater box and on some of those it is motor controlled, but it sounds like the flap is not switching back and forth

Bleed your cooling system. You have a air pockets in your system. Don't forget to run your heater full blast when doing so. Usually help to unplug your heater hose and flush out the heater core then work on getting it filled and getting all the air out of your system.

Buy a book from the parts store for 20.00, Autozone has the clymer paperbacks. Make sure the book covers what you want first

change the water pump and check for a blockage in the waterjacket

Sounds like your temperature actuator is not moving or your temp door is broken. On max a-c ,coolant is shut off to your heater core allowing only cold air in.

change your Heater Control Valve. I've seen a quite a few of them do this and it's almost always the valve